power: set no-show-all to TRUE on wifi and mobile rows
requested to merge jonathankang/gnome-control-center:wip/jonathankang/power-auto-show-hide-rows into master
The Wi-Fi and mobile broadband row's visibility depends on related device status. But calling gtk_widget_show_all on the whole list box makes them visible even related device is not avialbe. Fix that by setting no-show-all of these two widgets as TRUE.