* Path preference change was enqueued every time, interface config
  change and hence, preference would be overwritten, because of this.
  Removed the code to enqueue explicit path preference change.
  Instead copy config driven field in local vm add change path.
  Added test case for same.
Closes-bug:#1379481

Change-Id: If82fe39ee0be7ecdd8671150f886dcb0402d3b43
Merge "* Path preference change was enqueued every time, interface config   change and hence, preference would be overwritten, because of this.   Removed the code to enqueue explicit path preference change.   Instead copy config driven field in local vm add change path.   Added test case for same. Closes-bug:#1379481"