Add missing cert to guardian bundle

[pasanw]

Description

Fixes regression introduced by #3808, where the Calico API server cert was removed from the Guardian CA bundle

Release Note

Fixed an issue where Guardian was missing the certificate of the Calico API server from it's CA bundle. This issue only impacted clusters that were created using an older version of the Operator that did not use a centralized signer.

For PR author

• Tests for change.
• If changing pkg/apis/, run make gen-files
• If changing versions, run make gen-versions

For PR reviewers

A note for code reviewers - all pull requests must have the following:

• Milestone set according to targeted release.
• Appropriate labels:
  • kind/bug if this is a bugfix.
  • kind/enhancement if this is a a new feature.
  • enterprise if this PR applies to Calico Enterprise only.