Ensure that we use SF Vsync Choreographer for the PiP transition.

- Move the bounds animation onto the animation thread
- Remove existing code referencing the old sf-vsync choreographer
- Add ability for ValueAnimator subclasses to reference a different
  AnimationHandler, which uses a different FrameCallbackProvider with the
  sf-vsync choreographer in the animations that require it
- Ensure that PiP touch events are batched and sent aligned with the
  sf-vsync
- Move GC onto its own thread to not block other BackgroundThread calls

Bug: 36371375
Test: android.server.cts.ActivityManagerPinnedStackTests
Test: bit FrameworksServicesTests:com.android.server.wm.BoundsAnimationControllerTests
Test: go/wm-smoke

Change-Id: I6a41b35a4e4d4d6dbea82c2673452825fe3ffa58