Limit IPv4/IPv6 Prefix length in case of contrail deployment

OpenContrail do not allow configuration of AAP with prefix
length less then 24/120 (IPv4/IPv6) according to bug#1720118

Change-Id: I0a9ca8343d5773174e3a3b3239cb52d9cbeb3bc2
Closes-bug: PROD-21672
1 file changed