Dynamic output switcher chip and bug fixes

- Update the output switcher view to show the current device name and icon
- Show the requested buttons in mini player view
- Handle missing art or different number of buttons when changing tracks
- Catch NPEs for missing media metadata

Fixes: 143235162
Test: manual

Change-Id: I6fec4955a965a2011b6a02cb22f14a291afd1a18