This change relaxes the constraint that all subnets of the same
address family on a network must be allocated from the same subnet
pool. It allows subnets that share the same address scope to
co-exist on a network. If there is no address scope involved the
subnet pool / network affinity constraints continue to enforced
as done previously.
Change-Id: I33bd17c723b3e8d409415bda008440f8ed9cfa68
Closes: 1830240
Implements: subnets-different-pools-same-net
32182010c2