message: fix(aio): add polyfill for GoogleBot
  I chose to use unknown=polyfill option as per recommendation found at
diff: <!-- End Google Analytics -->
  <script>
  - window.onerror = function (message, url, lineNo, colNo, error) {
  - var container = document.createElement('div');
  -
  - container.style.color = 'red';
  - container.style.position = 'fixed';
  - container.style.background = '#eee';
  - container.style.padding = '2em';
  - container.style.top = '3em';
  - container.style.left = '1em';
  -
  - var msg = document.createElement('pre');
  - msg.innerText = [
  - 'UA: ' + window.navigator.userAgent,
  - 'Message: ' + message,
  - 'URL: ' + url,
  - 'Line: ' + lineNo,
  - 'Column: ' + colNo,
  - 'Stack: ' + (error && error.stack)
  - ].join('\n');
  -
  - container.appendChild(msg);
  -
  - setTimeout(function() {document.body.appendChild(container)}, 0);
  - };
  -
  - if (window.document.documentMode) {
  + /**
  + * Send a blocking request to fetch polyfill. We call this only on non-evergreen browsers.
  + */
  + function polyfillBrowser(polyfillUrl) {
  var script = document.createElement('script');
  - script.src = 'generated/ie-polyfills.min.js';
  + script.src = polyfillUrl;
  document.head.appendChild(script);
  }
  + if (window.document.documentMode) {
  + // polyfill IE11
  + polyfillBrowser('generated/ie-polyfills.min.js');
  + } else if (!Object.assign) {
  + // polyfill googlebot
  + polyfillBrowser('https://cdn.polyfill.io/v2/polyfill.min.js?unknown=polyfill');
  + }
  </script>
  </head>
  <body>
  