Display "Android Auto" in Connected Devices summary text.

Android Auto will be exposing a Settings tile under Connected Devices -> Connection Preferences.
If the Setting tile is available, then the summary text will reflect that.

Tested with additional unit tests and manually validated the scenarios by
flashing crosshatch-eng and disabling/enabling the relevant features.

Fix: 153896447
Test: Added unit coverage for new scenarios
Test: make RunSettingsRoboTests
Test: manually verified by flashing crosshatch-eng and disabling/enabling relevant components
Change-Id: I5a129c41b98ba435bc159a72c9a7c2dfd646ecd3