title: GPG error: http://packages.cloud.google.com/apt EXPKEYSIG 3746C208A7317B0F
body: <p>I get the following error when running <code>sudo apt update</code> on Debian.</p>
  
  <pre><code>GPG error: http://packages.cloud.google.com/apt cloud-sdk-stretch InRelease:
  The following signatures were invalid: EXPKEYSIG 3746C208A7317B0F
  </code></pre>