Update list_pref_setting_popup.xml

Add Transparency to Camera Settings :)

Original :- http://4.bp.blogspot.com/-822Befh3a_0/UcFAYRVh-UI/AAAAAAAAAc8/6PSEErEcGZ0/s1600/Screenshot_2013-06-19-10-34-23.png

After Commit :- https://lh6.googleusercontent.com/-vqB3cNToUTc/UcFWb2_oVwI/AAAAAAAAMcg/b_3z2siHmLw/w499-h831-no/Screenshot_2013-06-19-02-56-28.png

Thanks bajee :)