camera: Squashed ZSL updates from Steve Kondik

camera: ZSL and focus fixes

 * Drop the use of the touchaf-aec parameter entirely. No camera needs
   this anymore.
 * Only autofocus before a snap if we are actually in "auto" mode.
 * Change ZSL from a preference to an overlay boolean.

camera: Actually fix ZSL :)

Change-Id: I921c10e2dfd8694fc13ba8bc9def59c498322f4f

Conflicts:
	res/values/config.xml
	src/com/android/camera/CameraSettings.java
	src/com/android/camera/FocusOverlayManager.java
	src/com/android/camera/PhotoMenu.java
	src/com/android/camera/PhotoModule.java
	src/com/android/camera/util/CameraUtil.java