Camera2: Fix burst mode, auto scene detect layout

* Prevent icons from stacking ontop of each other

Change-Id: I4a1c8ae360c7272bfa2833aaf64410a2778a7ff7
camera: Add metadata-based ASD

 * New cameras use the metadata callback to report the
   detected scene mode. Add support for this.
 * The asdModes array must be set for this to work, which
   should contain the ordered list of possible scenes,
   corresponding to the camera_asd_values array.

Change-Id: I07279ae30a4cbedef02bec702252eb7e2abacd4a