shellDBus: Allow GNOME portal to access Shell D-Bus API

This will be necessary for a global shortcuts implementation.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3598>

js/ui/shellDBus.js

@@ -25,6 +25,7 @@ export class GnomeShell {
         this._senderChecker = new DBusSenderChecker([
             'org.gnome.Settings',
             'org.gnome.SettingsDaemon.MediaKeys',
+            'org.freedesktop.impl.portal.desktop.gnome',
         ]);
 
         this._extensionsService = new GnomeShellExtensions();