fix: add event listener to add admin related configuration

config/event_listeners.yaml

@@ -3,6 +3,12 @@ services:
         autowire: true
         autoconfigure: true
 
+    #
+    # System Settings
+    #
+
+    Pimcore\Bundle\AdminBundle\EventListener\AdminConfigListener: ~
+
     #
     # SECURITY
     #

src/EventListener/AdminConfigListener.php

@@ -0,0 +1,53 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * Pimcore
+ *
+ * This source file is available under two different licenses:
+ * - GNU General Public License version 3 (GPLv3)
+ * - Pimcore Commercial License (PCL)
+ * Full copyright and license information is available in
+ * LICENSE.md which is distributed with this source code.
+ *
+ *  @copyright  Copyright (c) Pimcore GmbH (http://www.pimcore.org)
+ *  @license    http://www.pimcore.org/license     GPLv3 and PCL
+ */
+
+namespace Pimcore\Bundle\AdminBundle\EventListener;
+
+use Pimcore;
+use Pimcore\Event\SystemEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\EventDispatcher\GenericEvent;
+
+/**
+ * @internal
+ */
+class AdminConfigListener implements EventSubscriberInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static function getSubscribedEvents(): array
+    {
+        return [
+            SystemEvents::GET_SYSTEM_CONFIGURATION => 'updateSystemConfiguration'
+        ];
+    }
+
+    public function updateSystemConfiguration(GenericEvent $event): void
+    {
+        $arguments = $event->getArguments();
+        $config = $arguments['settings'];
+
+        if (!$config || !$container = Pimcore::getContainer()) {
+            return;
+        }
+
+        $adminConfig = $container->getParameter('pimcore_admin.config');
+        $configuration = array_merge_recursive($config, $adminConfig);
+
+        $event->setArgument('settings', $configuration);
+    }
+}