Implement notifySystemPropertiesChanged

This is a Test API that notifies of updates to the system properties
when requested, received by callers of
SystemProperties#addChangeCallback

Test: atest android.view.inputmethod.cts.InputMethodStatsTest; check
logs for ImeTracker onProgress entries during text execution only

Change-Id: I8b81194524de822eab7538aab68675a677b5fd6d

core/api/test-current.txt

@@ -131,6 +131,7 @@ package android.app {
     method @RequiresPermission(allOf={android.Manifest.permission.PACKAGE_USAGE_STATS, android.Manifest.permission.INTERACT_ACROSS_USERS_FULL}, conditional=true) public int getUidProcessState(int);
     method public void holdLock(android.os.IBinder, int);
     method public static boolean isHighEndGfx();
+    method public void notifySystemPropertiesChanged();
     method @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER) public void removeHomeVisibilityListener(@NonNull android.app.HomeVisibilityListener);
     method @RequiresPermission(android.Manifest.permission.RESET_APP_ERRORS) public void resetAppErrors();
     method public static void resumeAppSwitches() throws android.os.RemoteException;

core/java/android/app/ActivityManager.java

@@ -5366,6 +5366,31 @@ public class ActivityManager {
         return PowerExemptionManager.REASON_DENIED;
     }
 
+    /**
+     * Notifies {@link #getRunningAppProcesses app processes} that the system properties
+     * have changed.
+     *
+     * @see SystemProperties#addChangeCallback
+     *
+     * @hide
+     */
+    @TestApi
+    public void notifySystemPropertiesChanged() {
+        // Note: this cannot use {@link ServiceManager#listServices()} to notify all the services,
+        // as that is not available from tests.
+        final var binder = ActivityManager.getService().asBinder();
+        if (binder != null) {
+            var data = Parcel.obtain();
+            try {
+                binder.transact(IBinder.SYSPROPS_TRANSACTION, data, null /* reply */,
+                        0 /* flags */);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+            data.recycle();
+        }
+    }
+
     /**
      * A subset of immutable pending intent information suitable for caching on the client side.
      *