Set cinder coordination backend url
Set cinder coordination backend url

If DLM is enabled, cinder should be configured to use the correct
backend url for the dlm.
At the moment only zookeeper is supported, as it is the only backend
currently supported in devstack.

Change-Id: I7afc8dc95bc5b3f11b888e10607615c1212c45f4

openstack-dev/devstack,group-policy/devstack,dtroyer/devstack,bswartz/devstack,group-policy/devstack,openstack-dev/devstack,dtroyer/devstack,richliu/devstack,richliu/devstack,noironetworks/devstack,nawawi/openstack,bswartz/devstack,noironetworks/devstack,nawawi/openstack