* Pickup nat destination vrf as source vrf for setting egress composite
  NH, while DNAT is happening.
* Test case for same

Change-Id: I3a340e90457d20e99555827506fda34742b41e3f
Merge "* Pickup nat destination vrf as source vrf for setting egress composite   NH, while DNAT is happening. * Test case for same" into R1.10