Defer a couple of Surface actions for WSAnimator.

Perform the set-transparent-region-hint operation outside of the
WindowManagerService loop. This is to isolate the Surface operation
from the WindowManagerService inner loop.

Similarly, defer the setWallpaperOffset call so it's animation is not
coupled to the WindowManagerService inner loop.

Note that both operations are still being done on the
WindowManagerService thread.

Change-Id: I97f030b2a9b7cffe91c77342a299bfac6e59e9f8