Enable BYO NSG

User Story:

As a (user persona), I want to be able to:

• Use a pre-existing network security group when creating an Azure cluster

so that I can achieve

•  more network flexibility in my Hosted Control planes deployment

Acceptance Criteria:

Description of criteria:

• Able to specify network security group when creating Azure cluster
• Able to specify network security group when creating Azure infra

(optional) Out of Scope:

Detail about what is specifically not being delivered in the story

Engineering Details:

• (optional) https://github/com/link.to.enhancement/
• (optional) https://issues.redhat.com/link.to.spike
• Engineering detail 1
• Engineering detail 2

This requires/does not require a design proposal.
This requires/does not require a feature gate.