Consume video frames

An input device currently reads video frames, and stores them into local
queue. We limit the queue size to 10 frames.

Here, we add the step where an input mapper would consume the video
frames from the video device for a given input device, and then pass
them onto the input listener.

Test: integration tested by checking that frames are processed correctly
in input hal. To check if frames are processed correctly, look at the
active touch area and print a log message when the total area exceeds a
certain threshold.
Bug: 111480215

Change-Id: Ifc519389e12b44540e9a54fd273241f9f7cd057d