Epic Goal

On P, verify that adding nodes day 2 to agent-based installer installed clusters works. See https://issues.redhat.com/browse/AGENT-682 for more details on the general goal. The goal of this epic is to verify this on P
None of the previous work restricts architecture or platform in a way that would exclude P, but there is no explicit epic for verifying that this works on P. This was a 4.16 Dev Preview and 4.18 GAed item.

Why is this important?

• Improved Day2 Support for Agent-based installer

Previous Work (Optional):
1. There has already been work on https://issues.redhat.com/browse/OCPSTRAT-784 - [Dev Prev] Simplify and unify adding nodes to clusters on day 2
2. There is an OCPSTRAT for GAing this in 4.18 and backporting to 4.16 https://issues.redhat.com/browse/OCPSTRAT-1528 - [GA OpenShift 4.16] Simplify and unify adding nodes to clusters on day 2
3. https://issues.redhat.com/browse/OCPSTRAT-1316 - GA OCPSTRAT (not available anymore?)

Done Checklist

• CI - For new features (non-enablement), existing Multi-Arch CI jobs are not broken by the Epic
• Release Enablement: <link to Feature Enablement Presentation>
• DEV - Upstream code and tests merged: <link to meaningful PR orf GitHub Issue>
• DEV - Upstream documentation merged: <link to meaningful PR or GitHub Issue>
• DEV - If the Epic is adding a new stream, downstream build attached to advisory: <link to errata>
• QE - Test plans in Test Plan tracking software (e.g. Polarion, RQM, etc.): <link or reference to the Test Plan>
• QE - Automated tests merged: <link or reference to automated tests>
• QE - QE to verify documentation when testing
• DOC - Downstream documentation merged: <link to meaningful PR>
• All the stories, tasks, sub-tasks and bugs that belong to this epic need to have been completed and indicated by a status of 'Done'.