Implement ability of OpenStack services to use redis via TLS as their caching backend.

[fdobrovolny]

Epic #462

Blocked by #489

As a SCS Operator, I want to use ansible Kolla to deploy OpenStack Services with Redis backend over TLS to have E2E encryption of OpenStack services.

Definition of Ready:

• [ ] User Story is clear and understood by the whole team
• [ ] Acceptance criteria are defined
• [ ] Acceptance criteria are clear and understood by the whole team

Definition of Done:

• [x] Ansible Kolla is able to deploy OpenStack services with Redis as a caching backend over TLS
• [ ] The patch has been submitted to upstream and merged.
• [ ] Change has been included in the testbed.
• [ ] CI tests have run successfully
• [ ] Documentation has been updated
• [ ] Release Notes have been updated

[fdobrovolny]

After a discussion with @MatusJenca2, it seems like an upstream change in Oslo caching backend will be needed to provide this functionality, and we decided to split this task into separate issue #489 just focusing on the ability to have Redis as caching backend and when upstream changes are implemented this issue can be revisited.

[MatusJenca2]

Upstream issues - they are split to individual openstack services

• Keystone
• Heat
• Placement
• Nova