Take care of updating from old component name, and don't let this happen
again.
Also tweak how we switch between static wallpapers to avoid introducing
a 4MB allocation in the system UI process when this happens -- we now
stop the current wallpaper service and start a new one, so we get a
brand new surface that we can draw only one time in to.
Change-Id: I6fc8a42b8a46bba79759bd68fb7d0684b5d897b7
9ea3163973