Fix bar visibility after restarting immersive activities

This was a result of using the wrong systemUiVisibility listener.
Instead, DecorView now follows the structure in ActionBarOverlayLayout,
where we use onWindowSystemUiVisibilityChanged for everything.

Bug: 17494017
Change-Id: I1be9165c5ff80021f3a7889d3811cf0c54f68e71