Adds gtag code to resolve occasional unit test failures from race condition

src/index.html

@@ -5,6 +5,10 @@
   <title>CR Connect - Configuration</title>
   <base href="/">
   <script>
+    window.dataLayer = window.dataLayer || [];
+    function gtag(){dataLayer.push(arguments);}
+    gtag('js', new Date());
+
     const ENV = {
       homeRoute: '$HOME_ROUTE',
       production: '$PRODUCTION',