Summary:
Added the changes to create a new root and client root CA if passed null in the api payload when the customer expects YBA to create a new root CA itself.
Original commit: d0c47ec9f75fc9a4b9fa6c3c3821887caa28410e / D47808

Test Plan: Tested manually

Reviewers: anabaria

Reviewed By: anabaria

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D47871