Report move to display for activities that handle config changes

When activity that is moved between displays handles all configuration
changes, it won't be restarted. This CL adds a callback to the client
to notify it about display change. Usually it will be followed by
onConfigurationChanged, except when configuration didn't actually change.
When activity is recreated, it won't receive onMovedToDisplay.

Bug: 34862802
Test: android.server.cts.ActivityManagerDisplayTests
Test: #testOnMovedToDisplayCallback
Change-Id: I9a9501cab788623ada15a31efb53e4b2378639fe
diff --git a/test-runner/src/android/test/mock/MockContext.java b/test-runner/src/android/test/mock/MockContext.java
index 9ffd92d..6bcd08a 100644
--- a/test-runner/src/android/test/mock/MockContext.java
+++ b/test-runner/src/android/test/mock/MockContext.java
@@ -739,6 +739,12 @@
         throw new UnsupportedOperationException();
     }
 
+    /** @hide */
+    @Override
+    public void updateDisplay(int displayId) {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public File[] getExternalFilesDirs(String type) {
         throw new UnsupportedOperationException();