Variable to config: system.performance [d7]

  update_variables_to_config('system.performance', array(
    'cache' => 'cache.page.use_internal',
    'page_cache_maximum_age' => 'cache.page.max_age',
    'page_compression' => 'response.gzip',
    'preprocess_css' => 'css.preprocess',
    'preprocess_js' => 'js.preprocess',
    'stale_file_threshold' => 'stale_file_threshold',
  ));

See parent issue #2181257: [meta] Variables to config migration [d7] for instructions.