Convert android device object to string before calling battor device mapping
Convert android device object to string before calling battor device mapping

Review-Url: https://codereview.chromium.org/2132003003

catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult-csm,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult-csm,catapult-project/catapult,benschmaus/catapult,catapult-project/catapult,sahiljain/catapult,sahiljain/catapult,catapult-project/catapult,sahiljain/catapult,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,sahiljain/catapult,benschmaus/catapult,sahiljain/catapult,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,benschmaus/catapult,benschmaus/catapult,sahiljain/catapult