Adding a check for vRouters single datasource to send forceRefresh request only if the previous request for cached-summary was successful. Added a flag dsObj['clean'].

Change-Id: Idb3984dd00b5466efa38abc5dda4e82d691e209b
Merge "Adding a check for vRouters single datasource to send forceRefresh request only if the previous request for cached-summary was successful. Added a flag dsObj['clean']."