Add missing SettingsLib strings

For the following RouteListingPreference constants
- SUBTEXT_ERROR_UNKNOWN
- SUBTEXT_DEVICE_LOW_POWER
- SUBTEXT_UNAUTHORIZED
- SUBTEXT_TRACK_UNSUPPORTED

Bug: 266923039
Test: atest MediaOutputAdapterTest MediaOutputControllerTest MediaOutputBaseDialogTest MediaOutputDialogTest
Change-Id: I0c7d910d4f3e9a05b8fdbfe8b9d86fbb4a9f9cf9