- getNumberofCamera is now  working
-  You can select which camera you want. ( note: camera_id should be 1 for tracking camera )
-  Set resolution
-  Set Manual exposure and gain
-  Default FPS is 30.
-  Every frames gives out timestamp.
- per frame meta-data api getFrameGainValue, getFrameExposuretime
- Set preview format using API
- Preview and video callback
- Add metadata related fields for encoder

Change-Id: I303665fe783d74d12733880ea002c5d334952a03
CRs-Fixed: 2018085