Keyguard: Bring back fast unlock

Change-Id: I927426e9078c9cc07cc582c74bc170bff6eb834e
KeyguardViewMediator: Play lock screen sound sooner

When the screen is locked, there is a long pause before the lock
sound actually plays. This makes that sound happen much sooner.

Change-Id: I62547a183d68b93a33651c4078b5788d324055a9