idle: do not attempt to turn off screen on Linux
idle: do not attempt to turn off screen on Linux

In the teardown, if screen_off was not set, only ensure that the
screen is on for Android targets.

lisatn/workload-automation,lisatn/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,lisatn/workload-automation,setrofim/workload-automation,lisatn/workload-automation,setrofim/workload-automation,ARM-software/workload-automation