[Flexiglass] disable tests in media carousel interactor

These tests are covering code that exists when scene container is disabled

Flag: com.android.systemui.scene_container
Fixes: 440314959
Test: atest SystemUiRoboTests:MediaCarouselInteractorTest
Change-Id: I4e20b3f0c2d68a5ff08e6edbefe2b4b9ba7f3ae0