This was created as a clone of https://issues.redhat.com/browse/OSPRH-7417

OSPRH-7417 is concerned with the "Storage-NFS" network. This is a new network that needs to be created via ci-framwork and exposed to tenants.

This Jira concerns exposing the existing "storage" network to tenants as an OpenStack provider network.

A few manila scenario tests create VMs and mount Manila shares inside these VMs and perform data read/writes. To mount the shares, the VMs must be able to access the shares. In case of the Native CephFS protocol, the shares are exposed on the ceph public network, also known as the "storage" network on CI-Framework deployments.

Manila's tempest tests are capable of creating VMs with two interfaces:

• one on a private network - to SSH into the VM to perform actions/verifications, and
• one on the storage network - so the VM can reach out to the ceph cluster and mount CephFS shares

https://opendev.org/openstack/manila-tempest-plugin/src/branch/master/manila_tempest_tests/config.py#L99

The network should be mapped on top of the underlying networks (storage). This basically means porting the following code which did the same step in the tripleo/director world:
https://github.com/rhos-infra/cloud-config/blob/master/post_tasks/create_manila_network.yml