Fix audio routing can not work after the phone get rebooted
Root Cause: setPreferredDeviceForStrategy() need to be called when hearing device get connected.
Solution:
* Call setPreferredDeviceForStrategy() when HearingAidDeviceManager#onProfileConnectionStateChangedIfProcessed()
* Extract the common functions into SettingsLib
Bug: 269122580
Test: make RunSettingsRoboTests
ROBOTEST_FILTER="(CachedBluetoothDeviceManagerTest|HearingAidAudioRoutingHelperTest|HearingAidDeviceManagerTest)"
Change-Id: I622040384f56f61c65f0daac45735789d637b703
8 files changed
