Improve logging for Output Switcher.

- Log MediaRouter callbacks and produced data in InfoMediaManager
- Log suggested device events in LocalMediaManager
- Add MediaDevice#toString
- Add RouteListingPreference.Item#toString
- Rename properties in MediaDevice.

Bug: 422074183
Test: manually, with logcat from a local device.
Flag: EXEMPT logs, variable renaming
Change-Id: Ib7d1ad552f0993cee777fae7d69d74dcbe2fc031