SensorService VTS: Add test for getDefaultSensor

The previous CL relies on getSensorList instead of getDefaultSensor
to find an accelerometer sensor with matching conditions. Test
coverage for getDefaultSensor is missing. Add it back.

Bug: 154370035
Test: run it
Change-Id: I9077819690de9dfdd7fdf1efb26ef1977739809c
1 file changed