Camera: Cleanup hardware key shutter handling

* Fix power shutter behaviour in camcorder mode
* Disable volume change while in camcorder mode, volume buttons should only
handle camera operations while in the camera

On devices with a hardware camera key:
* Disable power & volume shutter features
* Volume buttons control the zoom

On devices without a hardware camera key:
* When power shutter is disabled, volume buttons control the shutter (like AOSP)
* When power shutter is enabled, volume buttons control the zoom

Change-Id: I141946d5b6f5aec8b1e9a9f99270d30295596079
Camera: Fix key handling in panorama mode

* Disable volume change while in panorama mode, the popup makes preview glitch
* Enable hardware camera key handling to start/stop the panorama

Change-Id: I9a69f6bcbead8a499ad3b2874109907b0aca6b5b
Camera: scale capture review thumbnail  properly

* Capture review thumbnail is scaled to a square aspect ratio currently.
* This patch attempts to correct the scaling based on the canvas size.

Change-Id: I9ffe5320eef5d27f4a8abc07e47bf51a61ded859
camera: Support for OPPO camera features

 * Beauty mode, which does skin tone smoothing on detected faces
 * Slow shutter, which takes a long capture

TODO:
 * These features are mutually exclusive with HDR.
 * Create a submenu of toggles under where HDR lives now.

Change-Id: Ia5fcde86b84819fc9e008215f41711146465d5e5
Merge branch 'cm-10.2' into martincz