uibench: Added parameter to allow action(s)

Created by: mcgeagh

By default when running uibench, no user action is performed during the tests. This adds an optional parameter called 'action' and performs the actions as input events. This parameter can take the form of a list and allows you to perform multiple actions in a set order too.

E.g. When performing ActivityTransition test, action=['tap', 'tap'] will perform two taps in the centre of the screen which will maximise a thumbnail then minimise the resulting fullscreen image.