phpbb_extension_metadata_manager uses hard coded language for exceptions

throw new phpbb_extension_exception('The required file does not exist: ' . $this->metadata_file);

throw new phpbb_extension_exception('The required file does not exist: ' . $this->metadata_file);

throw new phpbb_extension_exception('file_get_contents failed on ' . $this->metadata_file);

throw new phpbb_extension_exception('json_decode failed on ' . $this->metadata_file);