Fix keyguard bugs

Integrate from proto app

Get some layout/alignment right between security views, bouncer,
etc. Expand the space available for the more cramped security views
when not in the bouncer.

Fix bug 7434391 - don't allow widget swiping in bouncer mode. Fix a
few other bouncer-related state tracking problems as well.

Use layers when moving the security view around.

Change-Id: Ied14bab8bb5c3d997c734a3ae657b766c427253f