diff --git a/core/api/current.txt b/core/api/current.txt
index 272fab303911b..a6849fe9686fc 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -19594,7 +19594,7 @@ package android.hardware.display {
   public final class VirtualDisplayConfig implements android.os.Parcelable {
     method public int describeContents();
     method public int getDensityDpi();
-    method @NonNull public java.util.List<java.lang.String> getDisplayCategories();
+    method @NonNull public java.util.Set<java.lang.String> getDisplayCategories();
     method public int getFlags();
     method public int getHeight();
     method @NonNull public String getName();
@@ -19609,7 +19609,7 @@ package android.hardware.display {
     ctor public VirtualDisplayConfig.Builder(@NonNull String, @IntRange(from=1) int, @IntRange(from=1) int, @IntRange(from=1) int);
     method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder addDisplayCategory(@NonNull String);
     method @NonNull public android.hardware.display.VirtualDisplayConfig build();
-    method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder setDisplayCategories(@NonNull java.util.List<java.lang.String>);
+    method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder setDisplayCategories(@NonNull java.util.Set<java.lang.String>);
     method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder setFlags(int);
     method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder setRequestedRefreshRate(@FloatRange(from=0.0f) float);
     method @NonNull public android.hardware.display.VirtualDisplayConfig.Builder setSurface(@Nullable android.view.Surface);
diff --git a/core/java/android/companion/virtual/VirtualDeviceManager.java b/core/java/android/companion/virtual/VirtualDeviceManager.java
index 6cc4c8a24c48d..90681cba7d832 100644
--- a/core/java/android/companion/virtual/VirtualDeviceManager.java
+++ b/core/java/android/companion/virtual/VirtualDeviceManager.java
@@ -545,12 +545,13 @@ public final class VirtualDeviceManager {
                 @VirtualDisplayFlag int flags,
                 @Nullable @CallbackExecutor Executor executor,
                 @Nullable VirtualDisplay.Callback callback) {
-            VirtualDisplayConfig config = new VirtualDisplayConfig.Builder(
+            VirtualDisplayConfig.Builder builder = new VirtualDisplayConfig.Builder(
                     getVirtualDisplayName(), width, height, densityDpi)
-                    .setSurface(surface)
-                    .setFlags(flags)
-                    .build();
-            return createVirtualDisplay(config, executor, callback);
+                    .setFlags(flags);
+            if (surface != null) {
+                builder.setSurface(surface);
+            }
+            return createVirtualDisplay(builder.build(), executor, callback);
         }
 
         /**
diff --git a/core/java/android/hardware/display/VirtualDisplayConfig.java b/core/java/android/hardware/display/VirtualDisplayConfig.java
index 6b56a067a1982..067ae4d438ccd 100644
--- a/core/java/android/hardware/display/VirtualDisplayConfig.java
+++ b/core/java/android/hardware/display/VirtualDisplayConfig.java
@@ -27,13 +27,13 @@ import android.media.projection.MediaProjection;
 import android.os.Handler;
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.util.ArraySet;
 import android.view.Display;
 import android.view.Surface;
 
-import java.util.ArrayList;
 import java.util.Collections;
-import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 
 /**
  * Holds configuration used to create {@link VirtualDisplay} instances.
@@ -51,8 +51,8 @@ public final class VirtualDisplayConfig implements Parcelable {
     private final Surface mSurface;
     private final String mUniqueId;
     private final int mDisplayIdToMirror;
-    private final boolean mWindowManagerMirroring;
-    private ArrayList<String> mDisplayCategories = null;
+    private final boolean mWindowManagerMirroringEnabled;
+    private ArraySet<String> mDisplayCategories = null;
     private final float mRequestedRefreshRate;
 
     private VirtualDisplayConfig(
@@ -64,8 +64,8 @@ public final class VirtualDisplayConfig implements Parcelable {
             @Nullable Surface surface,
             @Nullable String uniqueId,
             int displayIdToMirror,
-            boolean windowManagerMirroring,
-            @NonNull ArrayList<String> displayCategories,
+            boolean windowManagerMirroringEnabled,
+            @NonNull ArraySet<String> displayCategories,
             float requestedRefreshRate) {
         mName = name;
         mWidth = width;
@@ -75,7 +75,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         mSurface = surface;
         mUniqueId = uniqueId;
         mDisplayIdToMirror = displayIdToMirror;
-        mWindowManagerMirroring = windowManagerMirroring;
+        mWindowManagerMirroringEnabled = windowManagerMirroringEnabled;
         mDisplayCategories = displayCategories;
         mRequestedRefreshRate = requestedRefreshRate;
     }
@@ -151,8 +151,8 @@ public final class VirtualDisplayConfig implements Parcelable {
      * if DisplayManager should record contents instead.
      * @hide
      */
-    public boolean isWindowManagerMirroring() {
-        return mWindowManagerMirroring;
+    public boolean isWindowManagerMirroringEnabled() {
+        return mWindowManagerMirroringEnabled;
     }
 
     /**
@@ -161,8 +161,8 @@ public final class VirtualDisplayConfig implements Parcelable {
      * @see Builder#setDisplayCategories
      */
     @NonNull
-    public List<String> getDisplayCategories() {
-        return Collections.unmodifiableList(mDisplayCategories);
+    public Set<String> getDisplayCategories() {
+        return Collections.unmodifiableSet(mDisplayCategories);
     }
 
     /**
@@ -185,8 +185,8 @@ public final class VirtualDisplayConfig implements Parcelable {
         dest.writeTypedObject(mSurface, flags);
         dest.writeString8(mUniqueId);
         dest.writeInt(mDisplayIdToMirror);
-        dest.writeBoolean(mWindowManagerMirroring);
-        dest.writeStringList(mDisplayCategories);
+        dest.writeBoolean(mWindowManagerMirroringEnabled);
+        dest.writeArraySet(mDisplayCategories);
         dest.writeFloat(mRequestedRefreshRate);
     }
 
@@ -210,7 +210,7 @@ public final class VirtualDisplayConfig implements Parcelable {
                 && Objects.equals(mSurface, that.mSurface)
                 && Objects.equals(mUniqueId, that.mUniqueId)
                 && mDisplayIdToMirror == that.mDisplayIdToMirror
-                && mWindowManagerMirroring == that.mWindowManagerMirroring
+                && mWindowManagerMirroringEnabled == that.mWindowManagerMirroringEnabled
                 && Objects.equals(mDisplayCategories, that.mDisplayCategories)
                 && mRequestedRefreshRate == that.mRequestedRefreshRate;
     }
@@ -219,7 +219,7 @@ public final class VirtualDisplayConfig implements Parcelable {
     public int hashCode() {
         int hashCode = Objects.hash(
                 mName, mWidth, mHeight, mDensityDpi, mFlags, mSurface, mUniqueId,
-                mDisplayIdToMirror, mWindowManagerMirroring, mDisplayCategories,
+                mDisplayIdToMirror, mWindowManagerMirroringEnabled, mDisplayCategories,
                 mRequestedRefreshRate);
         return hashCode;
     }
@@ -236,7 +236,7 @@ public final class VirtualDisplayConfig implements Parcelable {
                 + " mSurface=" + mSurface
                 + " mUniqueId=" + mUniqueId
                 + " mDisplayIdToMirror=" + mDisplayIdToMirror
-                + " mWindowManagerMirroring=" + mWindowManagerMirroring
+                + " mWindowManagerMirroringEnabled=" + mWindowManagerMirroringEnabled
                 + " mDisplayCategories=" + mDisplayCategories
                 + " mRequestedRefreshRate=" + mRequestedRefreshRate
                 + ")";
@@ -251,9 +251,8 @@ public final class VirtualDisplayConfig implements Parcelable {
         mSurface = in.readTypedObject(Surface.CREATOR);
         mUniqueId = in.readString8();
         mDisplayIdToMirror = in.readInt();
-        mWindowManagerMirroring = in.readBoolean();
-        mDisplayCategories = new ArrayList<>();
-        in.readStringList(mDisplayCategories);
+        mWindowManagerMirroringEnabled = in.readBoolean();
+        mDisplayCategories = (ArraySet<String>) in.readArraySet(null);
         mRequestedRefreshRate = in.readFloat();
     }
 
@@ -283,8 +282,8 @@ public final class VirtualDisplayConfig implements Parcelable {
         private Surface mSurface = null;
         private String mUniqueId = null;
         private int mDisplayIdToMirror = DEFAULT_DISPLAY;
-        private boolean mWindowManagerMirroring = false;
-        private ArrayList<String> mDisplayCategories = new ArrayList<>();
+        private boolean mWindowManagerMirroringEnabled = false;
+        private ArraySet<String> mDisplayCategories = new ArraySet<>();
         private float mRequestedRefreshRate = 0.0f;
 
         /**
@@ -370,8 +369,8 @@ public final class VirtualDisplayConfig implements Parcelable {
          * @hide
          */
         @NonNull
-        public Builder setWindowManagerMirroring(boolean windowManagerMirroring) {
-            mWindowManagerMirroring = windowManagerMirroring;
+        public Builder setWindowManagerMirroringEnabled(boolean windowManagerMirroringEnabled) {
+            mWindowManagerMirroringEnabled = windowManagerMirroringEnabled;
             return this;
         }
 
@@ -383,7 +382,7 @@ public final class VirtualDisplayConfig implements Parcelable {
          * {@link android.content.pm.ActivityInfo#requiredDisplayCategory}.
          */
         @NonNull
-        public Builder setDisplayCategories(@NonNull List<String> displayCategories) {
+        public Builder setDisplayCategories(@NonNull Set<String> displayCategories) {
             mDisplayCategories.clear();
             mDisplayCategories.addAll(Objects.requireNonNull(displayCategories));
             return this;
@@ -435,7 +434,7 @@ public final class VirtualDisplayConfig implements Parcelable {
                     mSurface,
                     mUniqueId,
                     mDisplayIdToMirror,
-                    mWindowManagerMirroring,
+                    mWindowManagerMirroringEnabled,
                     mDisplayCategories,
                     mRequestedRefreshRate);
         }
diff --git a/media/java/android/media/projection/MediaProjection.java b/media/java/android/media/projection/MediaProjection.java
index 9e9012e431119..d70e8b36afdb5 100644
--- a/media/java/android/media/projection/MediaProjection.java
+++ b/media/java/android/media/projection/MediaProjection.java
@@ -191,7 +191,7 @@ public final class MediaProjection {
             } else {
                 session = ContentRecordingSession.createTaskSession(launchCookie);
             }
-            virtualDisplayConfig.setWindowManagerMirroring(true);
+            virtualDisplayConfig.setWindowManagerMirroringEnabled(true);
             final DisplayManager dm = mContext.getSystemService(DisplayManager.class);
             final VirtualDisplay virtualDisplay = dm.createVirtualDisplay(this,
                     virtualDisplayConfig.build(), callback, handler, windowContext);
diff --git a/services/companion/java/com/android/server/companion/virtual/GenericWindowPolicyController.java b/services/companion/java/com/android/server/companion/virtual/GenericWindowPolicyController.java
index 1c4602803426f..34033e225b805 100644
--- a/services/companion/java/com/android/server/companion/virtual/GenericWindowPolicyController.java
+++ b/services/companion/java/com/android/server/companion/virtual/GenericWindowPolicyController.java
@@ -134,7 +134,7 @@ public class GenericWindowPolicyController extends DisplayWindowPolicyController
     private final ArraySet<RunningAppsChangedListener> mRunningAppsChangedListeners =
             new ArraySet<>();
     @Nullable private final SecureWindowCallback mSecureWindowCallback;
-    @Nullable private final List<String> mDisplayCategories;
+    @Nullable private final Set<String> mDisplayCategories;
 
     private final boolean mShowTasksInHostDeviceRecents;
 
@@ -178,7 +178,7 @@ public class GenericWindowPolicyController extends DisplayWindowPolicyController
             @NonNull ActivityBlockedCallback activityBlockedCallback,
             @NonNull SecureWindowCallback secureWindowCallback,
             @NonNull IntentListenerCallback intentListenerCallback,
-            @NonNull List<String> displayCategories,
+            @NonNull Set<String> displayCategories,
             boolean showTasksInHostDeviceRecents) {
         super();
         mAllowedUsers = allowedUsers;
diff --git a/services/companion/java/com/android/server/companion/virtual/VirtualDeviceImpl.java b/services/companion/java/com/android/server/companion/virtual/VirtualDeviceImpl.java
index 2d010cf66e9be..b338d89a01696 100644
--- a/services/companion/java/com/android/server/companion/virtual/VirtualDeviceImpl.java
+++ b/services/companion/java/com/android/server/companion/virtual/VirtualDeviceImpl.java
@@ -97,6 +97,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 import java.util.function.Consumer;
 
 
@@ -830,7 +831,7 @@ final class VirtualDeviceImpl extends IVirtualDevice.Stub
     }
 
     private GenericWindowPolicyController createWindowPolicyController(
-            @NonNull List<String> displayCategories) {
+            @NonNull Set<String> displayCategories) {
         final GenericWindowPolicyController gwpc =
                 new GenericWindowPolicyController(FLAG_SECURE,
                         SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS,
diff --git a/services/core/java/com/android/server/display/VirtualDisplayAdapter.java b/services/core/java/com/android/server/display/VirtualDisplayAdapter.java
index 364d53ba3c10a..eda15ae32c8b0 100644
--- a/services/core/java/com/android/server/display/VirtualDisplayAdapter.java
+++ b/services/core/java/com/android/server/display/VirtualDisplayAdapter.java
@@ -285,7 +285,7 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
             mUniqueIndex = uniqueIndex;
             mIsDisplayOn = surface != null;
             mDisplayIdToMirror = virtualDisplayConfig.getDisplayIdToMirror();
-            mIsWindowManagerMirroring = virtualDisplayConfig.isWindowManagerMirroring();
+            mIsWindowManagerMirroring = virtualDisplayConfig.isWindowManagerMirroringEnabled();
         }
 
         @Override
diff --git a/services/tests/servicestests/src/com/android/server/companion/virtual/VirtualDeviceManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/companion/virtual/VirtualDeviceManagerServiceTest.java
index 2967c5c53e8ad..339ccd80c351d 100644
--- a/services/tests/servicestests/src/com/android/server/companion/virtual/VirtualDeviceManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/companion/virtual/VirtualDeviceManagerServiceTest.java
@@ -130,7 +130,6 @@ import org.mockito.MockitoAnnotations;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.List;
 import java.util.Set;
 import java.util.function.Consumer;
 
@@ -283,7 +282,7 @@ public class VirtualDeviceManagerServiceTest {
         return blockedActivities;
     }
 
-    private Intent createRestrictedActivityBlockedIntent(List displayCategories,
+    private Intent createRestrictedActivityBlockedIntent(Set<String> displayCategories,
             String targetDisplayCategory) {
         when(mDisplayManagerInternalMock.createVirtualDisplay(any(), any(), any(), any(),
                 eq(NONBLOCKED_APP_PACKAGE_NAME))).thenReturn(DISPLAY_ID_1);
@@ -1634,7 +1633,7 @@ public class VirtualDeviceManagerServiceTest {
 
     @Test
     public void nonRestrictedActivityOnRestrictedVirtualDisplay_startBlockedAlertActivity() {
-        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(List.of("abc"),
+        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(Set.of("abc"),
                 /* targetDisplayCategory= */ null);
         verify(mContext).startActivityAsUser(argThat(intent ->
                 intent.filterEquals(blockedAppIntent)), any(), any());
@@ -1642,7 +1641,7 @@ public class VirtualDeviceManagerServiceTest {
 
     @Test
     public void restrictedActivityOnRestrictedVirtualDisplay_doesNotStartBlockedAlertActivity() {
-        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(List.of("abc"), "abc");
+        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(Set.of("abc"), "abc");
         verify(mContext, never()).startActivityAsUser(argThat(intent ->
                 intent.filterEquals(blockedAppIntent)), any(), any());
     }
@@ -1650,14 +1649,14 @@ public class VirtualDeviceManagerServiceTest {
     @Test
     public void restrictedActivityOnNonRestrictedVirtualDisplay_startBlockedAlertActivity() {
         Intent blockedAppIntent = createRestrictedActivityBlockedIntent(
-                /* displayCategories= */ List.of(), "abc");
+                /* displayCategories= */ Set.of(), "abc");
         verify(mContext).startActivityAsUser(argThat(intent ->
                 intent.filterEquals(blockedAppIntent)), any(), any());
     }
 
     @Test
     public void restrictedActivityNonMatchingRestrictedVirtualDisplay_startBlockedAlertActivity() {
-        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(List.of("abc"), "def");
+        Intent blockedAppIntent = createRestrictedActivityBlockedIntent(Set.of("abc"), "def");
         verify(mContext).startActivityAsUser(argThat(intent ->
                 intent.filterEquals(blockedAppIntent)), any(), any());
     }
diff --git a/services/tests/servicestests/src/com/android/server/companion/virtual/audio/VirtualAudioControllerTest.java b/services/tests/servicestests/src/com/android/server/companion/virtual/audio/VirtualAudioControllerTest.java
index d9e4da73c1c30..2bfa44ecb1d6d 100644
--- a/services/tests/servicestests/src/com/android/server/companion/virtual/audio/VirtualAudioControllerTest.java
+++ b/services/tests/servicestests/src/com/android/server/companion/virtual/audio/VirtualAudioControllerTest.java
@@ -89,7 +89,7 @@ public class VirtualAudioControllerTest {
                         /* activityBlockedCallback= */ null,
                         /* secureWindowCallback= */ null,
                         /* intentListenerCallback= */ null,
-                        /* displayCategories= */ new ArrayList<>(),
+                        /* displayCategories= */ new ArraySet<>(),
                         /* showTasksInHostDeviceRecents= */ true);
     }
 
diff --git a/services/tests/servicestests/src/com/android/server/display/DisplayManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/display/DisplayManagerServiceTest.java
index 7971fd71ea090..de1c2195fcdba 100644
--- a/services/tests/servicestests/src/com/android/server/display/DisplayManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/display/DisplayManagerServiceTest.java
@@ -967,7 +967,7 @@ public class DisplayManagerServiceTest {
         final VirtualDisplayConfig.Builder builder2 = new VirtualDisplayConfig.Builder(
                 VIRTUAL_DISPLAY_NAME, width, height, dpi)
                 .setUniqueId(uniqueId2)
-                .setWindowManagerMirroring(true);
+                .setWindowManagerMirroringEnabled(true);
         final int secondDisplayId = binderService.createVirtualDisplay(builder2.build(),
                 mMockAppToken2 /* callback */, null /* projection */,
                 PACKAGE_NAME);