Epic Goal

• Our/OCP's use of a private DNS zone prevents customers from overriding the vnet DNS. This PR removes private DNS zones from our architecture. The goal is to remove this dependency so that they can use their own DNS

Why is this important?

• Customers are looking to be able to point to internal DNS (internal registry or resources). This fix enables them to do so. 

Scenarios

1. ...

Previous Work (Optional):

1. https://github.com/Azure/ARO-RP/pull/1296 

2. Installer specific patches: https://github.com/openshift/enhancements/pull/654 

Open questions::

Done Checklist

• CI - CI is running, tests are automated and merged.
• Release Enablement <link to Feature Enablement Presentation>
• DEV - Upstream code and tests merged: <link to meaningful PR or GitHub Issue>
• DEV - Upstream documentation merged: <link to meaningful PR or GitHub Issue>
• DEV - Downstream build attached to advisory: <link to errata>
• QE - Test plans in Polarion: <link or reference to Polarion>
• QE - Automated tests merged: <link or reference to automated tests>
• DOC - Downstream documentation merged: <link to meaningful PR>