skip VR HAL test if there's no a::h::vr@ service process on a target

device

Test: make vts -j10 && vts-tradefed run commandAndExit vts
--skip-all-system-status-check --primary-abi-only --skip-preconditions
--module VrHidlTargetTest -l INFO

Change-Id: Ic4c8f6c6707269e64910e93b4601b9d43de01714