/**
  * update the fields pulled from form xml to match fields used for query for advanced grid
  * @param array $fields filterFields - original fields pulled from form xml
  * @param array $filterFields filterFields - filter fields' values
  * @param array $sortFields filterFields - sort fields' values
  * @return array - an array with updated field names for advanced grid
  */
 protected function _getFieldsForAdvancedGrid($fields, $filterFields, $sortFields)
 {
     $fields = parent::_getFieldsForAdvancedGrid($fields, $filterFields, $sortFields);
     $fields = ['photo.fileStorageId' => ['label' => 'photo', 'type' => 'image', 'isFilterField' => 1, 'isSortField' => 0, 'filterOrder' => -1, 'sortOrder' => 999, 'position' => 'left']] + $fields;
     // include photo field
     return $fields;
 }