88579e2558
The core thing is to find out a way to update group when devices (bt device and usb device)are updated. The infrastructure contains three parts: 1. ConnectedDeviceController Normal PreferenceController. Get info from sub controller and update the preferenceGroup. 2. BluetoothDeviceUpdater Listen to bluetooth callback, decide whether to add/remove devices 3. DevicePreferenceCallback Interface to add/remove preference. This interface will be used in ConntectedDeviceController and future SavedDeviceController Bug: 69333961 Test: RunsettingsRoboTests Change-Id: I85a9ef216a801d5f0dd1cf0130d53850a68be4bd