[contrail/contrail-utils] Install dns utils scripts

Refs:
  https://review.opencontrail.org/#/c/344/
  https://review.opencontrail.org/#/c/345/

Change-Id: Ibaa8a1e82d9e773283b123e9507cbfd37b2ec1ed
(cherry picked from commit 2e7dc2862cc9be62a2a08ef858884fe959c248b6)