settings: Don't use G_VARIANT_BUILDER_INIT
settings: Don't use G_VARIANT_BUILDER_INIT

This is glib 2.50 or higher, which doesn't exist on xenial.

flatpak/xdg-desktop-portal,matthiasclasen/xdg-desktop-portal,matthiasclasen/xdg-desktop-portal,flatpak/xdg-desktop-portal,matthiasclasen/xdg-desktop-portal,flatpak/xdg-desktop-portal,flatpak/xdg-desktop-portal,matthiasclasen/xdg-desktop-portal,matthiasclasen/xdg-desktop-portal