Add additional exposure modes to QCameraExposure.

[ChangeLog][GStreamer][Android] Camera exposure mode extended to support
Action, Landscape, NightPortrait, Theatre, Sunset, SteadyPhoto,
Fireworks, Party, Candlelight, and Barcode modes.

Change-Id: I13d4bb042d27c0bd2ffcd369882b56bbabc84335
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>