Description of problem:

When deploying Ceph nodes via OSP-director, the deployment fails in task tripleo-bootstrap with following message:

TASK [tripleo-bootstrap : Deploy required packages to bootstrap TripleO] *******                                                                                                      [294/617]
Wednesday 01 April 2020  14:08:26 +0200 (0:00:00.634)       0:00:37.179 ******* 
fatal: [overcloud-cephstorage-2]: FAILED! => {"changed": false, "failures": ["No package openvswitch available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results
": []} 
fatal: [overcloud-cephstorage-0]: FAILED! => {"changed": false, "failures": ["No package openvswitch available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results
": []} 
fatal: [overcloud-cephstorage-1]: FAILED! => {"changed": false, "failures": ["No package openvswitch available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results
": []}                                                                                                                                                                              


Version-Release number of selected component (if applicable):

tripleo-ansible-0.4.2-0.20200207140443.b750574.el8ost.noarch


How reproducible:
always


Steps to Reproduce:
1. Configure an overcloud to use overcloud-minimal for Ceph nodes https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.0/html/director_installation_and_usage/creating-a-basic-overcloud-with-cli-tools#using-the-overcloud-minimal-image-to-avoid-using-a-Red-Hat-subscription-entitlement

Actual results:
Deployment fails due to missing subscription for a repo with openvswitch


Expected results:
Deployment succeeds without requiring openvswitch


Additional info:
The issue is that openvswitch is hardcoded as a dependency: https://github.com/openstack/tripleo-ansible/blob/stable/train/tripleo_ansible/roles/tripleo-bootstrap/vars/redhat-8.yml#L21