[kots] Allow to add custom CA no matter which TLS option is selected

[corneliusludmann]

Currently, in KOTS (Replicated) we allow to add custom CA certs only when you bring our own (probably self-signed) cert. For the case someone has an SCM with a self-signed cert but uses Cert-Manager for the Gitpod certs, there is no option to add the CA for the SCM to Gitpod. We could fix this by giving the option to add a custom CA in any case (no matter which cert you use for Gitpod) as long as it's fine to add additional custom CAs to Gitpod even when Gitpod itself uses a cert not signed by this custom CA.

This has to be tested and implemented in the KOTS config after https://github.com/gitpod-io/gitpod/issues/9604 has been fixed.

[Pothulapati]

@corneliusludmann Is this important?

I think the main blocker for this is the that when a user uses the cert-manager options, We need to load the cert-manager CA, and hence we don't provide this option all together.

We can fix this by, Expanding the internal cert loading options to load a list of certificates and not just one.