Add wallpaper pickers to seperate package [2/2]

Change-Id: I233b90aa52b5a8c408fa3adfe3bdad07330cc2ad
(cherry picked from commit f23be04ba805ba32a10165f2eb007dead6421d9e)

Conflicts:
	res/xml/lockscreen_interface_settings.xml
	res/xml/theme_settings.xml