Update GTAG in conf.py instead of layout.html (#2474)

Author: Svetlana Karslioglu

_templates/layout.html

@@ -1,22 +1,7 @@
 {% extends "!layout.html" %}
 
-{%- block extrahead %}
-{{ super() }}
-<!-- Google Tag Manager -->
-<script>(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-T8XT4PS');</script>
-<!-- End Google Tag Manager -->
-{% endblock %}
 
 {%- block content %}
-<!-- Google Tag Manager (noscript) -->
-<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-T8XT4PS"
-height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
-<!-- End Google Tag Manager (noscript) -->
-
 {{ super() }}
 <script>
 if((window.location.href.indexOf("/prototype/")!= -1) && (window.location.href.indexOf("/prototype/prototype_index")< 1))

conf.py

@@ -217,7 +217,7 @@ def reset_seeds(gallery_conf, fname):
     'display_version': True,
     'navigation_with_keys': True,
     'logo_only': False,
-    'analytics_id': 'UA-117752657-2',
+    'analytics_id': 'GTM-T8XT4PS',
 }