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