Fix configuration of camera settings in camerabin backend.

Fix configuration of camera settings in camerabin backend.

Enable gstphotography interfaces if the compile check passes, and
implement missing pieces of whitebalance and focus configuration.

Change-Id: Icd24dfd148204f8d8218176593c3120427a13e1e
Reviewed-by: John Brooks <john.brooks@dereferenced.net>
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>