Add Preview to templates-sdk develop nav and global nav in templates-sdk-dev. Remove dependence on -includePreview.

Change-Id: I1456c3c94522f58c7d1c899ff96dd95cdc6ada7c
diff --git a/tools/droiddoc/templates-sdk-dev/assets/js/docs.js b/tools/droiddoc/templates-sdk-dev/assets/js/docs.js
index c634a3b..6c19b4d 100644
--- a/tools/droiddoc/templates-sdk-dev/assets/js/docs.js
+++ b/tools/droiddoc/templates-sdk-dev/assets/js/docs.js
@@ -4447,6 +4447,8 @@
       } else {
         selected = parentNavEl.removeClass('has-subnav').addClass('selected');
       }
+    } else if (body.hasClass('preview')) {
+      selected = navEl.find('> li.preview > a').addClass('selected');
     }
     return $(selected);
   };