Fixes for ending PiP animation.

During the PiP animation, we have two basic requirements:
   1. We need to scale windows to the pinned stack bounds.
   2. We need to halt resize and movement notifications to the client.
As we end the animation, we need to disable these states at differing
times. First we need to deliver a final resize and movement notification
to the client for it's new position. However, Surfaces may not
immediately resize (in particular in the case of child windows,
it may be some time!), furthermore Surfaces may resize at different
times so we need to persist scaling on a Surface by Surface
basis after reenabling resize notifications.

Bug: 28559097
Change-Id: I6d52a3e213e08a34f4c0eea892b2a84cd4c20e18