File _service of Package gn

<services>
  <service name="obs_scm" mode="manual">
    <param name="scm">git</param>
    <param name="url">https://gn.googlesource.com/gn.git</param>
    <param name="revision">e4702d7409069c4f12d45ea7b7f0890717ca3f4b</param>
    <param name="versionformat">0.%cd</param>
    <param name="changesgenerate">enable</param>
  </service>
  <service name="tar" mode="buildtime"/>
  <service name="recompress" mode="buildtime">
    <param name="compression">xz</param>
    <param name="file">*.tar</param>
  </service>
  <service name="set_version" mode="manual"/>
</services>