File _service of Package balena-etcher

<services>
  <service name="download_url">
    <param name="url">https://github.com/balena-io/etcher/releases/download/v1.18.11/balena-etcher-1.18.11.x86_64.rpm</param>
    <param name="filename">etcher-v1.18.11.rpm</param>
  </service>
</services>