The UI only shows the active LE device

At the media device, it only shows the active LE device which is
connected.

Bug: 232892046
Test: make RunSettingsRoboTests ROBOTEST_FILTER=AvailableMediaBluetoothDeviceUpdaterTest
make RunSettingsRoboTests ROBOTEST_FILTER=ConnectedBluetoothDeviceUpdaterTest
make RunSettingsRoboTests ROBOTEST_FILTER=SavedBluetoothDeviceUpdaterTest

Change-Id: Iac661206def4d43bc40ab9bb1938f084926899c2
Merged-In: Iac661206def4d43bc40ab9bb1938f084926899c2
7 files changed