BUG-1025 : use correct YANG syntax to avoid yangtools warnings.

Change-Id: Ic47bfb0d5fddd09c62ce271e8c48b2e31893c5a8
Signed-off-by: Dana Kutenicsova <dkutenic@cisco.com>
Merge "BUG-1025 : use correct YANG syntax to avoid yangtools warnings."