Hide windows immediately after policy visibility anim

We need to hide the surface in the same transaction when we finish
the hide animation, as otherwise we'll have a flicker, as it's
not guaranteed that layout transaction will happen in time.

Test: Open camera, make sure status bar disappears without flicker
Change-Id: I140214e26afaf90d09ed53da2b50ce4803dffb5c
1 file changed