Custom file types exported through Features are missing mimetype information.

In one of my custom Feature modules, I defined a custom file type in code, in the .module file. Then, I tried to re-export this file type through features in order to get it under the control of features. The result was the creation of a file named cw_media.file_type.inc containing an implementation of hook_file_default_types with the following:

/**
 * Implements hook_file_default_types().
 */
function cw_media_file_default_types() {
  $export = array();

  $file_type = new stdClass();
  $file_type->disabled = FALSE; /* Edit this to true to make a default file_type disabled initially */
  $file_type->api_version = 1;
  $file_type->type = 'archive';
  $file_type->label = 'Archive';
  $file_type->description = 'An <em>Archive</em> file is compressed data.';
  $export['archive'] = $file_type;

  return $export;
}

The mimetype information that I had originally added is missing. I tried editing the file type through the UI, and adding the mimetypes back in, then re-exporting the feature again. The mimetype information was still missing.

Currently, the only way I can do this is to implement hook_file_default_types_alter ontop of this to add in the mimetype information.