title: how to add custom security policy and referrer policy on nginx ingress
body: <p>i just try with configuration-snippet anotation but didn't work</p>
  <pre><code>nginx.ingress.kubernetes.io/configuration-snippet: |
    more_set_headers &quot;Content-Security-Policy: script-src 'self'&quot;;
    more_set_headers &quot;Referrer-Policy: 'same-origin';&quot;
    more_set_headers &quot;Feature-Policy: &quot;geolocation 'none'; vibrate 'none';&quot;;&quot;
  </code></pre>
  <p>is any other way?
  my nginx controller version is nginx-ingress:1.8.1 and running on gcp</p>