User Story:

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

• Allow the user to set the StackType from the InstallConfig
• This should include IPv4_ONLY, IPv4_IPv6, and (maybe) IPv6_ONLY - There is no use for this one so it may not be necessary

so that I can achieve

• Passing/Setting the correct value in the CAPG subnet spec 

Acceptance Criteria:

Description of criteria:

• Validate the user entered string from the Install Config
• Set the Subnet Spec based on this information.
• Default should be IPv4_ONLY

(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.