specify vehicle service name on vts test

The default service name assumed by the framework is lower case hal name (vehicle)
Since vehicle hal uses Upper case for its service name and is assumed by the framework side code, this change specifies a custom service name

Test: ENABLE_TREBLE=true make vts BUILD_GOOGLE_VTS=true -j32 && vts-tradefed run commandAndExit vts --skip-all-system-status-check --primary-abi-only --skip-preconditions --module VehicleHidlTest -l INFO
Change-Id: Ie02f83d27554e89b4a958421a1a88d701abcf2a7