CameraHal: Changes to 3A lock implementation

1) Only take user set values for AE and AWB locks. Decouple
interaction between AE/AWB locks and AF/takePicture/stopPreview
2) When in CAF mode, if we query AF and see that focus is already
locked, we do not have to call SetConfig for OMX_IndexConfigFocusControl.
Just return the status to upper layers instead.
3) If user doesn't call cancelAutoFocus after a doAutoFocus call, we
need to forcefully unlock AF to ensure we do a scan. This would also
essentially render CAF as normal auto AF.

bug:5356404

Change-Id: I5bb840ca0122d8a9387f72290d2b421703dba23d
Signed-off-by: Tyler Luu <tluu@ti.com>
3 files changed