LockScreen: allow hardware key longpress to put device to sleep

Change-Id: I201fd96ee0c40ec0f1b810ad32e22cf4fd82d8c8
SystemUI: Ignore lint check ProtectedPermissions

Change-Id: I8a663062a8f0d8ac0a31e40d8442bd74a3450785
SystemUI: Remove obsolete layout params (fix lint warning)

Change-Id: I4409049d4c0964209f11021e22f82fa179c3aaea
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.

Also modified Lock.ogg slightly to remove the initial silence.

Change-Id: Ib401d62f4e64c7a9f82557df06b60c5d427393f3