KeyguardViewMediator refactor

Continue dividing KeyguardViewMediator into smaller, testable
units, first by removing screen on/off calls that go here.
Consolidate screen on/off logic into one file. Add support to
Lifecycle to dispatch methods with 1 argument.

Bug: 195430376
Test: KeyguardViewMediatorTest ScreenLifecycleTest
Change-Id: I2696629fc7e1a3934503e8c94ecdeed749762769