Before this CL, If SIM doesn't have tethering option then UI will not
back to previous option when press "USB tethering" in
[Default USB configuration].
This CL added receiver to observe USB state that get correct state
from UsbManager.
Bug: 138630479
Test: make -j42 RunSettingsRoboTests
Change-Id: I6cc8da508f6ab142142ca8c28460125bad93925b