Added two commands to WA to record and replay input events using revent.
As part of this also added the ability to get a device model from
android and linux device. This may need to be improved in the future.
As of Android 6.0, apps can request permissions at runtime. If the
target device is running Android 6.0+ these permissions are now automatically
granted.
Added -p option to the list command. This alows filtering results by
supported platforms, e.g.
wa list workloads -p linux
Also adding missing supported_platforms attribute to various extensions.
If an extension does not have this attribute, the assumption is that it
is supported by all available platforms.
