[Android] add wrapper for workload-automation

Created by: mdigiorgio

Workload-automation (WA) already provides many workloads for Android targets. This is a wrapper for LISA to use WA.

In order to use one of the WA workloads (wa list workloads tells you what is available) you need to implement a <workload__class_name> class in a <workload_name>.py file stored under libs/utils/android/workloads.

<workload_class_name> inherits Wlauto and has to implement the methods from Workload and (eventually) Wlauto.

This way, the workload is visible by the Workload class that will list it as available and will eventually check that the related package is installed on the Android target.

Signed-off-by: Michele Di Giorgio michele.digiorgio@arm.com