Notify Output Switcher of suggested devices

Mark MediaDevices as suggested if they've been defined as such from the
API, and update the device list whenever there's an update to suggested
devices

Test: atest InfoMediaManagerTest
Bug: 394147501
Flag: com.android.media.flags.enable_suggested_device_api
Change-Id: I24df609f635559765f0261c8c159983f96d6e3f1