Update analytics tracking ID

The company managing site analytics for docs.openstack.org has
requested we update the tracking script snippet it uses. This
switches the existing implementation to the new version they
provided to the OpenInfra Foundation staff.

A similar change I201161a51ce4483c7bad4e16fbfb39493c4ca712 covers
the copy of this in the openstack-manuals repo.

Change-Id: I91104f6f0f287e09379f89ccf3a2b084fdde9465

openstackdocstheme/theme/openstackdocs/layout.html

@@ -4,17 +4,14 @@
 <meta name="viewport" content="width=device-width, initial-scale=1">
 {% include 'css.html' %}
 {% if theme_analytics_tracking_code %}
-<!-- Google Analytics -->
-<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', '{{ theme_analytics_tracking_code }}', 'auto');
-ga('send', 'pageview');
+<!-- Google tag (gtag.js) -->
+<script async src="https://www.googletagmanager.com/gtag/js?id={{ theme_analytics_tracking_code }}">
+</script>
+<script>
+window.dataLayer = window.dataLayer || [];
+function gtag(){dataLayer.push(arguments);} gtag('js', new Date());
+gtag('config', '{{ theme_analytics_tracking_code }}');
 </script>
-<!-- End Google Analytics -->
 {% endif %}
 {% endblock %}
 

openstackdocstheme/theme/openstackdocs/theme.conf

@@ -4,7 +4,7 @@ stylesheet = basic.css
 pygments_style = native
 
 [options]
-analytics_tracking_code = UA-17511903-1
+analytics_tracking_code = G-DD299CMF7V
 sidebar_mode = toctree
 display_badge = True
 display_toc = True

openstackdocstheme/theme/starlingxdocs/theme.conf

@@ -4,7 +4,7 @@ stylesheet = basic.css
 pygments_style = native
 
 [options]
-#analytics_tracking_code = UA-17511903-1
+#analytics_tracking_code = GA_CODE_HERE
 sidebar_mode = toctree
 display_badge = True
 display_toc = True