Make some APIs used by ExtService module @SystemApi

These are all pieces of data apps could get anyway;
these are code nice-to-haves to reduce code replication

Test: make
Bug: 122138479
Bug: 138589409
Change-Id: Ie8ffacb6c28840f779c68f7aa95f1405e70f5ce5

api/system-current.txt

@@ -513,6 +513,8 @@ package android.app {
   }
 
   public class Notification implements android.os.Parcelable {
+    method @Nullable public android.util.Pair<android.app.RemoteInput,android.app.Notification.Action> findRemoteInputActionPair(boolean);
+    method @NonNull public java.util.List<android.app.Notification.Action> getContextualActions();
     field public static final String CATEGORY_CAR_EMERGENCY = "car_emergency";
     field public static final String CATEGORY_CAR_INFORMATION = "car_information";
     field public static final String CATEGORY_CAR_WARNING = "car_warning";
@@ -521,6 +523,10 @@ package android.app {
     field public static final int FLAG_AUTOGROUP_SUMMARY = 1024; // 0x400
   }
 
+  public static final class Notification.MessagingStyle.Message {
+    method @Nullable public static android.app.Notification.MessagingStyle.Message getMessageFromBundle(@NonNull android.os.Bundle);
+  }
+
   public static final class Notification.TvExtender implements android.app.Notification.Extender {
     ctor public Notification.TvExtender();
     ctor public Notification.TvExtender(android.app.Notification);
@@ -543,6 +549,7 @@ package android.app {
     method public void populateFromXml(org.xmlpull.v1.XmlPullParser);
     method public org.json.JSONObject toJson() throws org.json.JSONException;
     method public void writeXml(org.xmlpull.v1.XmlSerializer) throws java.io.IOException;
+    field public static final int USER_LOCKED_SOUND = 32; // 0x20
   }
 
   public final class NotificationChannelGroup implements android.os.Parcelable {
@@ -6648,6 +6655,10 @@ package android.service.notification {
     field @NonNull public static final android.os.Parcelable.Creator<android.service.notification.SnoozeCriterion> CREATOR;
   }
 
+  public class StatusBarNotification implements android.os.Parcelable {
+    method public boolean isAppGroup();
+  }
+
 }
 
 package android.service.oemlock {

core/java/android/app/Notification.java

@@ -3278,6 +3278,7 @@ public class Notification implements Parcelable
      * @hide
      */
     @Nullable
+    @SystemApi
     public Pair<RemoteInput, Action> findRemoteInputActionPair(boolean requiresFreeform) {
         if (actions == null) {
             return null;
@@ -3304,7 +3305,8 @@ public class Notification implements Parcelable
      *
      * @hide
      */
-    public List<Notification.Action> getContextualActions() {
+    @SystemApi
+    public @NonNull List<Notification.Action> getContextualActions() {
         if (actions == null) return Collections.emptyList();
 
         List<Notification.Action> contextualActions = new ArrayList<>();
@@ -7730,7 +7732,8 @@ public class Notification implements Parcelable
              * @hide
              */
             @Nullable
-            public static Message getMessageFromBundle(Bundle bundle) {
+            @SystemApi
+            public static Message getMessageFromBundle(@NonNull Bundle bundle) {
                 try {
                     if (!bundle.containsKey(KEY_TEXT) || !bundle.containsKey(KEY_TIMESTAMP)) {
                         return null;

core/java/android/app/NotificationChannel.java

@@ -110,6 +110,7 @@ public final class NotificationChannel implements Parcelable {
     /**
      * @hide
      */
+    @SystemApi
     public static final int USER_LOCKED_SOUND = 0x00000020;
 
     /**

core/java/android/service/notification/StatusBarNotification.java

@@ -17,6 +17,7 @@
 package android.service.notification;
 
 import android.annotation.NonNull;
+import android.annotation.SystemApi;
 import android.annotation.UnsupportedAppUsage;
 import android.app.Notification;
 import android.app.NotificationManager;
@@ -172,6 +173,7 @@ public class StatusBarNotification implements Parcelable {
      *
      * @hide
      */
+    @SystemApi
     public boolean isAppGroup() {
         if (getNotification().getGroup() != null || getNotification().getSortKey() != null) {
             return true;