Use transitions for shade window occluded state

There is a timing issue that shows up with activity
launch animations. If keyguard occluded state is
changed in the middle of a launch animation, a flicker
can occur, sometimes pretty bad like currently
lauching the emergency call UI over SIM bouncer. Use
transition FINISHED state as a more reliable method
to send state over to the shade window.

Fixes: 344716537
Test: atest NotificationShadeWindowModelTest
Test: manual repeatedly launch emergency call UI
over SIM bouncer
Flag: com.android.systemui.use_transitions_for_keyguard_occluded

Change-Id: I14e1c3478fb76c3a9459c3a8fd0d8e4587962089