Fix ASHA Hearing aids connection status incorrect

Root Cause: After disconnecting one side of hearing aid, the mainDevice
did not update device side information from subDevice.

Solution: switch subDevice information to mainDevice.

Bug: 233708857
Test: make RunSettingsLibRoboTests ROBOTEST_FILTER=CachedBluetoothDeviceTest
Test: make RunSettingsLibRoboTests ROBOTEST_FILTER=HearingAidDeviceManagerTest
Change-Id: I5977c11828464863610cfdaabd91154b710b4151