title: Google Analytics on AMP does not send custom dimensions
body: <p>This used to work before but now when I add the following code snippet, from the Google Analytics AMP integration page, it does not make a network <code>collect</code> call for Google analytics <a href="https://developers.google.com/analytics/devguides/collection/amp-analytics/#extending_googleanalytics" rel="nofollow noreferrer">https://developers.google.com/analytics/devguides/collection/amp-analytics/#extending_googleanalytics</a></p>
  
  <pre><code>&lt;amp-analytics type="googleanalytics" id="analytics1"&gt;
  &lt;script type="application/json"&gt;
  {
    "requests": {
      "pageviewWithCd1Cd3": "${pageview}&amp;cd1=${cd1}&amp;cd3=${cd3}"
    },
    "vars": {
      "account": "UA-XXXXX-Y"
    },
    "triggers": {
      "trackPageviewWithCustom" : {
        "on": "visible",
        "request": "pageviewWithCd1Cd3",
        "vars": {
          "title": "Classic Cars",
          "cd1": "registeredUser",
          "cd3": "automotive"
        }
      }
    }
  }
  &lt;/script&gt;
  &lt;/amp-analytics&gt;
  </code></pre>
  
  <p>I replaced the account with a real account starting with <code>UA</code></p>
  
  <p>I also have the analytics script tag included in the head tag:</p>
  
  <pre><code>&lt;script async custom-element="amp-analytics" src="https://cdn.ampproject.org/v0/amp-analytics-0.1.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>The pageview does fire a request to <code>collect</code> but the <code>cd1</code> and <code>cd3</code> do not get included in the query params nor does the values of cd1 and cd3 get passed in the query params of the URL.</p>
  
  <p>Have others noticed this same issue starting November 17th onwards?</p>