ONOS-3128 : Web UI - Traffic overlay as default overlay.
- fixed bug in radiobuttonset which failed to update button selection state via programmatic selectedIndex() call.
- default overlay configured at beginning of topoToolbar.js

Change-Id: I54c82e402b3c3955c3d83a264c6d8ac14127ce70
diff --git a/web/gui/src/main/webapp/app/view/topo/topo.js b/web/gui/src/main/webapp/app/view/topo/topo.js
index 42b6f4b..0dfd628 100644
--- a/web/gui/src/main/webapp/app/view/topo/topo.js
+++ b/web/gui/src/main/webapp/app/view/topo/topo.js
@@ -525,6 +525,7 @@
 
             // temporary solution for persisting user settings
             restoreConfigFromPrefs();
+            ttbs.setDefaultOverlay();
 
             $log.debug('registered overlays...', tov.list());
             $log.log('OvTopoCtrl has been created');