[flexiglass] Add Shade Header clock text scaling transition and click behavior

Makes the Shade Header clock a shared element that scales up during Shade -> QS transition. Also adds the onclick action for the clock (launching the clock activity)

Bug: 299141272
Test: forthcoming
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT
Change-Id: I5108b630017464ff462fa318be4a25ab978803b0
17 files changed