Issue 6624: CM File manager: Mount RW does not work if i slide the slider from ro to rw.

Issue: http://code.google.com/p/cyanogenmod/issues/detail?id=6624
Changed onClickListener for OnCheckedChangeListener for the switch control.
The OnCheckedChangeListener listener handles both events: click and slide.

Change-Id: I9b8c81d4d7489fce2cbef1f4799a12266cb14acf