Transitions - Add doze transition information

Add a new DozeMachine.Part in order to emit granular doze state to the
KeyguardRepository. Use that new information to make better decisions
about when to transition state to/from dreaming.

Upcoming: Support for pulsing and dozing (non-AOD) states

Bug: 195430376
Test: atest KeyguardRepositoryImplTest
Change-Id: If759ba0d286eca907af615b9e2e56cadef224f4d