Consolidate setPhoto logic.

This makes the ViewHolder self-capable of updating/setting its
photo, so if we want to update the photo in the future (either
in teh scope of a listener, or in the ViewHolder itself), we
don't need to worry about configuring and passing around a
bunch of commands.

Bug: 23943480
Change-Id: I17653014dd81fcb9ae7a667539e40a9310a72d36