feat: Update Tag Manager to use new tracking code (#271)

web/index.html

@@ -56,12 +56,20 @@
 
   <title>I/O Pinball Machine - Flutter</title>
   <link rel="manifest" href="manifest.json">
-  <script async src="https://www.googletagmanager.com/gtag/js?id=UA-67589403-1"></script>
   <script>
-    window.dataLayer = window.dataLayer || [];
-    function gtag(){dataLayer.push(arguments);}
-    gtag('js', new Date());
-    gtag('config', 'UA-67589403-1');
+    (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+    new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+    j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+    'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+    })(window,document,'script','dataLayer','GTM-ND4LWWZ');
+  </script>
+  <script>
+    (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+    (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+    m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+    })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+    ga('create', 'UA-67589403-1', 'auto');
+    ga('send', 'pageview');
   </script>
   <script src="/__/firebase/8.9.1/firebase-app.js"></script>
   <script src="/__/firebase/8.9.1/firebase-firestore.js"></script>