cert-manager-cainjector hardening manifest

Summary

Updating to hardening manifest.

Definition of Done

Hardening:

• Container builds successfully
• Container version has been updated in greylist file
• Branch has been merged into development

Justifications:

• All findings have been justified per the above documentation
• Justifications have been provided to the container hardening team

Approval Process:

• Peer review from Container Hardening Team
• Findings Approver has reviewed and approved all justifications
• Approval request has been sent to Authorizing Official
• Approval request has been processed by Authorizing Official

/cc @ironbank-notifications/updates