Update listener que setea campo extraData

EventListener/SonataAdminConfigureListener.php

@@ -30,9 +30,11 @@ class SonataAdminConfigureListener
     {
         $formMapper = $event->getMapper();
         if ($formMapper->has('extraData')) {
-            $formMapper->addHelp('extraData', $this->trans('help.json_format'));
-            $extraDataField = $formMapper->get('extraData');
-            $extraDataField->setRequired(false);
+            $formMapper->add('extraData', null, [
+                'required' => false,
+                'label' => $this->trans('form.label_extra_data'),
+                'help' => $this->trans('help.json_format'),
+            ]);
         }
     }