xdg-shell: Place popups on the same screen
When opening g-c-c on the phone screen, going to power and selecting the blank screen
combo the selection list is placed on the 2nd screen. It should be on the same screen (since it's otherwise not selectable via touch). I've seen similar things with combo boxes in glade and two outputs on intel but this one is a simple to reproduce on the L5 or devkit with an external screen attached.