- this change moves the ovs_ensure_configured.sh  file to the
  openvswitch-db container.
- this change reorders the plays in ansible/roles/neutron/tasks/start.yml
  to configure the ovs bridges before starting the vswitchd container.

Change-Id: Ied1a82d48377534c15680406df9a96caf3b79515
Closes-Bug: #1522133