The SOURCE (search source identifier) constant is moving
from hidden in android.app.SearchManager to com.android.common.Search.
Part of http://b/issue?id=2429556
Change-Id: I68fa792f2d452aadcb9216f5c780bd082ca5039f
Now draws something a little nicer if the live wallpaper
doesn't have a preview.
Also: move Launcher2 back into "shared" so it has permission
to set the wallpaper.
This change requires changing the signature and shared user id of Launcher2, we
will have to revert this once we move the wallpapers picker back to Settings.
