ENGCOM-4275: Fix issue with custom option file uploading #21170

 - Merge Pull Request #21170 from nikolaevas/magento2:sys-tmp-fix
 - Merged commits:
   1. fa0a22d
   2. 2ed46ad

Author: magento-engcom-team

lib/internal/Magento/Framework/Filesystem/DirectoryList.php

@@ -96,7 +96,8 @@ public function __construct($root, array $config = [])
         static::validate($config);
         $this->root = $this->normalizePath($root);
         $this->directories = static::getDefaultConfig();
-        $this->directories[self::SYS_TMP] = [self::PATH => realpath(sys_get_temp_dir())];
+        $sysTmpPath = ini_get('upload_tmp_dir') ? ini_get('upload_tmp_dir') : sys_get_temp_dir();
+        $this->directories[self::SYS_TMP] = [self::PATH => realpath($sysTmpPath)];
 
         // inject custom values from constructor
         foreach ($this->directories as $code => $dir) {