feat: add OpenShift API credential to CaC

[ericcames]

Summary

Add an OpenShift/Kubernetes API Bearer Token credential to controller_credentials.yml so AAP can authenticate against an OpenShift cluster.

Details

Originally proposed in branch redawg-vault-updates by redawg. The credential would be inventory-driven:

- name: openshift API - {{ aap_username }}
  organization: "{{ my_organization }}"
  credential_type: OpenShift or Kubernetes API Bearer Token
  inputs:
    bearer_token: "{{ openshift_api_token }}"
    host: "{{ openshift_api_host }}"
    verify_ssl: true

Prerequisites

• Add openshift_api_token and openshift_api_host to the sample inventory group_vars/all.yml
• Document how to obtain the bearer token