Add a sound-playing method to Camera API.

To allow applications with non-standard Camera use cases to use the
platform sound files and routing, add a method to play any of the
standard Camera sounds (shutter, autofocus, record start/stop) using a
background thread.

Bug: 5447107
Change-Id: I2524853a626e3ce334a7aad2f7de061d5c04abd0