WindowManager: fix clipping

The animation code has some logic to avoid committing a new clip rect
when it hasn't changed. However, when we destroy the SurfaceControl and
recreate it later, we failed to reset the cached value, so if the clip
rect hasn't changed, we never set it on the new SurfaceControl.

This patch resets the cached value when creating the SurfaceControl.

Change-Id: I355576709834dd80994c7564330a234b182800e6