status/keyboard: Explicitly initialize ornament

Layout items use the ornament to indicate the active layout, so
their ornament should always be NONE or DOT.

The default is about to change to HIDDEN, so explicitly initialize
the ornament to NONE to keep the current radio item appearance.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2843>

js/ui/status/keyboard.js

@@ -28,6 +28,8 @@ class LayoutMenuItem extends PopupMenu.PopupBaseMenuItem {
     _init(displayName, shortName) {
         super._init();
 
+        this.setOrnament(PopupMenu.Ornament.NONE);
+
         this.label = new St.Label({
             text: displayName,
             x_expand: true,