Remove scene container code from MediaControlPanel

The scene container framework is using the new pipeline with
MediaControlViewBinder et al now, so this code is never used in practice

Flag: com.android.systemui.scene_container
Bug: 326408371
Test: use media controls with and without flag
Change-Id: I6e6d362e05c8efe5be2682d62e93a4c2b9f28f51
1 file changed