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
Keyguard: disable music transport control debug

Change-Id: Ia4361d0850334dc0944559c40409c9062cf02e47
Prevent lock/unlock sound during music playback

Lock/unlock sound mixes in with music and causes
lag and distortion.

Change-Id: I9d3582c6bf28aa62a5a6712bc9e89eb2f73e0288