[flexiglass] Revamp SharedNotificationContainerViewModelTest

- Adds an extension function which allows parameterizing SceneContainerFlag
- Adds parameterization to SharedNotificationContainerViewModelTest
- Disables some tests under scene container where we have flagged off the code

Bug: 332750091
Test: atest SystemUITest
Test: atest SystemUiRoboTest
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint TEAMFOOD
Change-Id: Ief5202cf04d3b7692593f3e15d8893ea3dee2a18