The usb updater listens to usb update and notify
ConnectedDeviceGroupController to add/remove
preference.
This cl:
1. Add ConntectedusbDeviceUpdater
2. Extract the UsbConnectionBroadcastReceiver since it would be
used both in controller and updater.
3. Add tests
Bug: 69333961
Test: RunSettingsRoboTests
Change-Id: Ic3b045a6faa4eba57d9b0c089ea1656141cc0220
988199e202