Only initialize PermissionUsageHelper lazily or when requested

This fixes a memory leak caused by automatically registering a
PermissionUsageHelper on PermissionManager instantiation.

Bug: 204222680
Test: manual
Change-Id: I94c6da3dd89e8b158552e94c94e4d0fb3f5d6f0d

core/java/android/permission/PermissionManager.java

@@ -180,8 +180,6 @@ public final class PermissionManager {
         mPermissionManager = IPermissionManager.Stub.asInterface(ServiceManager.getServiceOrThrow(
                 "permissionmgr"));
         mLegacyPermissionManager = context.getSystemService(LegacyPermissionManager.class);
-        //TODO ntmyren: there should be a way to only enable the watcher when requested
-        mUsageHelper = new PermissionUsageHelper(context);
     }
 
     /**
@@ -955,6 +953,29 @@ public final class PermissionManager {
         return mSplitPermissionInfos;
     }
 
+    /**
+     * Initialize the PermissionUsageHelper, which will register active app op listeners
+     *
+     * @hide
+     */
+    public void initializeUsageHelper() {
+        if (mUsageHelper == null) {
+            mUsageHelper = new PermissionUsageHelper(mContext);
+        }
+    }
+
+    /**
+     * Teardown the PermissionUsageHelper, removing listeners
+     *
+     * @hide
+     */
+    public void tearDownUsageHelper() {
+        if (mUsageHelper != null) {
+            mUsageHelper.tearDown();
+            mUsageHelper = null;
+        }
+    }
+
     /**
      * @return A list of permission groups currently or recently used by all apps by all users in
      * the current profile group.
@@ -965,7 +986,7 @@ public final class PermissionManager {
     @NonNull
     @RequiresPermission(Manifest.permission.GET_APP_OPS_STATS)
     public List<PermGroupUsage> getIndicatorAppOpUsageData() {
-        return mUsageHelper.getOpUsageData(new AudioManager().isMicrophoneMute());
+        return getIndicatorAppOpUsageData(new AudioManager().isMicrophoneMute());
     }
 
     /**
@@ -980,9 +1001,7 @@ public final class PermissionManager {
     @RequiresPermission(Manifest.permission.GET_APP_OPS_STATS)
     public List<PermGroupUsage> getIndicatorAppOpUsageData(boolean micMuted) {
         // Lazily initialize the usage helper
-        if (mUsageHelper == null) {
+        initializeUsageHelper();
-            mUsageHelper = new PermissionUsageHelper(mContext);
-        }
         return mUsageHelper.getOpUsageData(micMuted);
     }
 

core/java/android/permission/PermissionUsageHelper.java

@@ -176,6 +176,11 @@ public class PermissionUsageHelper implements AppOpsManager.OnOpActiveChangedLis
         return mUserContexts.get(user);
     }
 
+    public void tearDown() {
+        mAppOpsManager.stopWatchingActive(this);
+        mAppOpsManager.stopWatchingStarted(this);
+    }
+
     @Override
     public void onOpActiveChanged(@NonNull String op, int uid, @NonNull String packageName,
             boolean active) {

packages/SystemUI/src/com/android/systemui/dagger/FrameworkServicesModule.java

@@ -442,7 +442,11 @@ public class FrameworkServicesModule {
     @Provides
     @Singleton
     static PermissionManager providePermissionManager(Context context) {
-        return context.getSystemService(PermissionManager.class);
+        PermissionManager pm = context.getSystemService(PermissionManager.class);
+        if (pm != null) {
+            pm.initializeUsageHelper();
+        }
+        return pm;
     }
 
     @Provides