Allow for synchronously applying transactions with a SurfaceView

Exposing this allows for atomically updating a SurfaceControl hierarchy
when new frames arrive as the SurfaceView's content. For instance, a
streaming application can blank out the Surface when switching video
source files to prevent older frames from lingering.

Bug: 187309567
Test: SurfaceViewTests
Change-Id: I9b4df8b3312506f014f97c7f4a890b8242578ede