Fix failing search in filelist

To be removed after bug is fixed in ext:media

public/typo3conf/ext/ep_theme/Configuration/TCA/Overrides/sys_file.php

@@ -0,0 +1,10 @@
+<?php
+if (!defined('TYPO3_MODE')) die ('Access denied.');
+
+$tca = [
+    'ctrl' => [
+        'default_sortby' => 'name DESC'
+    ],
+];
+
+\TYPO3\CMS\Core\Utility\ArrayUtility::mergeRecursiveWithOverrule($GLOBALS['TCA']['sys_file'], $tca);