kolla: Fix ext-subnet allocation pools

Allocate neutron external subnet from a XX.XX.XX.51 to XX.XX.XX.250
in the neutron network defined in IDF. The other IPs can be used by
infrastructure. For e.g. kickstart and other devices can use the
range below XX.XX.XX.51.

Also the following updates have been made:
 - Enable cinder backup, and use nfs backup driver
 - Enable keystone security compliance

Hopefully this should fix some of the tempest failures

installer-type: kolla
deploy-scenario: os-nosdn-nofeature

Change-Id: Iffa202c821a24ce7b8e7cd0458b93b7a23af6d12
1 file changed