Add ActivityThreadClientTest to presubmit

Add tests to presubmit and mark as flaky. We will remove
the flaky annotation if stable.

Bug: 143153552
Test: atest FrameworksMockingCoreTests:android.app.activity.
      ActivityThreadClientTest
Change-Id: Ife07cfc8891184dcb6cf2b8444cd36fbfad7fdc9

core/tests/mockingcoretests/src/android/app/activity/ActivityThreadClientTest.java

@@ -46,10 +46,12 @@ import android.content.res.Configuration;
 import android.os.Binder;
 import android.os.RemoteException;
 import android.os.UserHandle;
+import android.platform.test.annotations.Presubmit;
 import android.view.WindowManagerGlobal;
 
 import androidx.test.annotation.UiThreadTest;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.FlakyTest;
 import androidx.test.filters.MediumTest;
 import androidx.test.platform.app.InstrumentationRegistry;
 
@@ -70,6 +72,8 @@ import org.mockito.quality.Strictness;
  */
 @RunWith(AndroidJUnit4.class)
 @MediumTest
+@Presubmit
+@FlakyTest(bugId = 143153552)
 public class ActivityThreadClientTest {
 
     @Test