Add unit test for ActivityStackSupervisor#testApplySleepTokensLocked.

This change adds a unit test to make sure the supervisor interacts
properly with the stacks when this method is invoked under various
conditions.

Change-Id: If0fbacfa4c8bc18ae85183a22edeec54d6f90dc4
Fixes: 74597379
Test: atest FrameworksServicesTests:com.android.server.am.ActivityStackSupervisorTests#testApplySleepTokensLocked
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java b/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
index c130592..6fb1b2e 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityTestsBase.java
@@ -353,22 +353,29 @@
      */
     protected static class TestActivityStackSupervisor extends ActivityStackSupervisor {
         private ActivityDisplay mDisplay;
+        private KeyguardController mKeyguardController;
 
         public TestActivityStackSupervisor(ActivityManagerService service, Looper looper) {
             super(service, looper);
             mDisplayManager =
                     (DisplayManager) mService.mContext.getSystemService(Context.DISPLAY_SERVICE);
             mWindowManager = prepareMockWindowManager();
+            mKeyguardController = mock(KeyguardController.class);
         }
 
         @Override
         public void initialize() {
             super.initialize();
-            mDisplay = new TestActivityDisplay(this, DEFAULT_DISPLAY);
+            mDisplay = spy(new TestActivityDisplay(this, DEFAULT_DISPLAY));
             attachDisplay(mDisplay);
         }
 
         @Override
+        public KeyguardController getKeyguardController() {
+            return mKeyguardController;
+        }
+
+        @Override
         ActivityDisplay getDefaultDisplay() {
             return mDisplay;
         }