Camera2: Tweak some strings

Taken from CameraNext resources

Change-Id: I5d3cd7f7ca0f08be39ba571826db3bae8019b333
Camera2: Fix default slow shutter option

Broken after http://review.cyanogenmod.org/63070

Change-Id: I611c1bd812ab1151fd91f3c758c0e3c357e3454f