workloads/jankbench: Ensure logcat monitor thread is terminated
workloads/jankbench: Ensure logcat monitor thread is terminated

Previously the LogcatRunMonitor left the logcat process running in the
background causing issues with concurrent accesses. Now ensure the thread
terminates correctly.

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