Folder: Fix top folder creation (#59422)

fix top folder creation

public/app/features/folders/components/NewDashboardsFolder.tsx

@@ -35,8 +35,11 @@ const pageNav: NavModelItem = {
 function NewDashboardsFolder({ createNewFolder }: Props) {
   const [queryParams] = useQueryParams();
   const onSubmit = (formData: FormModel) => {
-    createNewFolder(formData.folderName, String(queryParams['folderUid']));
+    const folderUid = typeof queryParams['folderUid'] === 'string' ? queryParams['folderUid'] : undefined;
+
+    createNewFolder(formData.folderName, folderUid);
   };
+
   const validateFolderName = (folderName: string) => {
     return validationSrv
       .validateNewFolderName(folderName)

public/app/features/search/components/DashboardActions.tsx

@@ -18,7 +18,7 @@ export const DashboardActions: FC<Props> = ({ folderUid, canCreateFolders = fals
       url = `dashboards/folder/new/`;
     }
 
-    if ((isTypeNewFolder && config.featureToggles.nestedFolders) || folderUid) {
+    if (folderUid) {
       url += `?folderUid=${folderUid}`;
     }