Support GONE->AOD animation

This ports the code in UnlockedScreenOffAnimationController to the
GoneToAodTransitionViewModel, and combines the translation values with
burn in.

ClockEventController is also changed to listen to keyguard transitions
instead of dozeAmount, behind the MIGRATE_KEYGUARD_STATUS_VIEW flag.

Also, fix issues with the WallPaperPicker preview mode not cleaning up
resources.

Fixes: 301473935
Test: atest GoneToAodTransitionViewModelTest
KeyguardRootViewModelTest
Test: test with all migration flags off to ensure no regressions

Change-Id: I21356667737c840edbd68ada4e0ff1c7f13a85cb