Fix transitions when communal ktf refactor enabled

This change removes the state syncing done by CommunalSceneStartable, in
favor of a more undirectional flow where KTF is determined by STL.

It also includes various fixes to ensure proper transitions when going
to edit mode, activity launches, and dismissing the hub when
unlocking.

Bug: 327225415
Flag: com.android.systemui.communal_scene_ktf_refactor
Test: atest CommunalSceneStartableTest
Test: atest KeyguardTransitionScenariosTest
Test: atest CommunalSceneTransitionInteractorTest
Change-Id: I51cd9410723ee2ff7eaab28730f9beb051626501