Fix issues related to clip rect used in animations

In particular this CL fixes two things:

1. Make clip rect in the coordinates of the target surface instead of
   the absoluate screen coordinates.
2. Avoid repetitively applying insets on the same instance of Rect that
   holds clip rect.

Bug: 232459537
Test: Animations of activity launches & dismisses look OK.
Change-Id: I311552f50780a000f4ef28098a2e3cc52889b147