add footer for dartdocs generated for the sdk for analytics and survey

tools/bots/dartdoc_footer.html

Index: tools/bots/dartdoc_footer.html
diff --git a/tools/bots/dartdoc_footer.html b/tools/bots/dartdoc_footer.html
new file mode 100644
index 0000000000000000000000000000000000000000..63de697d483dca8748a830b1e3b1232e04e14d14
--- /dev/null
+++ b/tools/bots/dartdoc_footer.html
@@ -0,0 +1,13 @@
+<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-26406144-9', 'auto');
+  ga('send', 'pageview');
+
+</script>
+
+<script async src="//survey.g.doubleclick.net/async_survey?site=4vq7qmqpfn4zjduve64c4h6lqa">
+</script>