SurfaceView Cleanup (3/n): Extract RemoteAccessibilityController

We extract the SurfaceControlViewHost accessibility logic from
SurfaceView. This is serving both cleaning up the code in SurfaceView
a little, while also serving the goal of one day using this
accessibility code from other components.

Test: Existing tests pass
Change-Id: I0333ab339e54e3766fffab25df92f00bdb9723dc