[Dual Shade] Add UMO (media controls) to the quick settings shade.

Fix: 395619022
Test: Manually tested by adding active media playback and observing it
 is rendered in quick settings shade.
Test: Added unit tests.
Test: Existing unit tests still pass.
Flag: com.android.systemui.scene_container
Change-Id: Ib42b7667b681125cff2bc1e6626a917de827813f