NuPlayerDriver: Maintain the timeStamp after seek

 While offload playback is going on, if user pause
 and seeks to new position before offload tear-down,
 on resume playback starts from old time-stamp

 Once tear-down happens NuPlayer loses updated time-stamp
 so while resuming it resumes playback with stale time-stamp.
 Make sure the updated time-stamp is maintained in
 NuPlayerDriver wich is used while starting the playback
 after resume.

Change-Id: I3451051f569264b21a43be81b01798fabed0182e