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: I922bd4db8b7f2c661cfa3de10a5810e171efa124
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']."