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
Merge "KeyguardViewMediator: Play lock screen sound sooner" into cm-11.0
Merge branch 'cm-11.0' into martincz