Smooth out tap-to-expand notification

In this case the SHADE_LOCKED state is being received prior
to expansion events, so wait for both events before issuing
a call to fade when closing the shade. And don't fade in
notifications if you do this while pulsing.

Also, move tests to multivalent directory

Test: atest SharedNotificationsViewModelTest
AodToLockscreenTransitionViewModelTest
Fixes: 325729047
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
DEVELOPMENT

Change-Id: Id81c1b662cfb31388f0d9d478e50fc0bc832e59f