Fix UMO does not show in GH

This change fixes the issue of UMO not showing in the Glanceable Hub
when scene container is enabled by:
- igoring legacy transition view models if scene container is enabled
- use the Composable UMO in the CommunalScene

Test: atest CommunalTransitionViewModelTest
Test: manually verified that UMO shows in the hub
Fix: 339450630
Flag: com.android.systemui.scene_container
Change-Id: I20f0ea1d9aab6d28fdc11a402f2716dbb09adf8e