docs: add the sidenav h2 back to the stylesheet for compatibility w/ javadocs

Change-Id: I37551efd09bea528200a93a8d3602ea11e63f140
diff --git a/tools/droiddoc/templates-sdk/assets/android-developer-docs.css b/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
index b470ba0..6cc4a97 100644
--- a/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
+++ b/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
@@ -72,7 +72,8 @@
   zoom:1;
 }
 
-#side-nav li span.heading {
+#side-nav li span.heading,
+#side-nav li h2 {
   display:block;
   font-size:12px;
   font-weight: bold;