Changes to OWNERS files for USB.

Ashish and Sarup have moved away from USB and often get pinged or assigned bugs under USB component. This also means we may miss important issues relevant to Android USB because they're assigned to them.
Adding myself and moving Arun lower in priority to OWNERS so that bugs will go through Mark, myself and Arun instead.

Change-Id: If8f3beb622ad4c2f9d18d2134b170f27194f542f