Camera: Fix removal of histogram setting

Histogram is disabled by default in config.xml, so the code to filter unsupported modes is never executed
Remove histogram option completely when it's disabled in config.xml

Change-Id: Id47da14d7d3d268e70727d25ed8f4d431b80f6f1

Conflicts:
	src/com/android/camera/CameraSettings.java
Camera: Fix the removal of histogram setting fix

Regroup conditionals to fix the NPE.

Change-Id: If87e5287b75a8f43c1a34f234aa0a8c405f43891

Conflicts:
	src/com/android/camera/CameraSettings.java