workloads: add jankbench
workloads: add jankbench

Add automation for Google's jankbench workload.

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