Ensure that PiP mode changed callback if animation is interrupted

- If a PiP enter animation callback is interrupted, the activity is never
  actually put into PiP mode, and will never receive
  onPictureInPictureModeChanged(false) even if enterPictureInPictureMode()
  returns true due to the change being deduped (it was never in that mode).
  In this specific case, force a callback to be made to the app so that it
  has a signal that it is no longer in PiP mode.

Bug: 63749396
Test: bit FrameworksServicesTests:com.android.server.wm.BoundsAnimationControllerTests
Test: android.server.cts.ActivityManagerPinnedStackTests
Test: #testEnterPipInterruptedCallbacks

Change-Id: I301c70e4fb0f2175dd6d7b5feae065b41df2878d