Allows managing keys as secrets

[nfrankel]

At the moment, the Apache APISIX Helm chart default values looks like:

admin:
  credentials:
    admin: edd1c9f034335f136f87ad84b625c8f1
    viewer: 4054f7cf07e344346cd3f287985e76a2

To override them, I need to set them "in clear".

It would be better to manage them as Kubernetes Secrets.

[tokers]

Make sense.

[tokers]

We need a way to fetch the secret data to the container, either from volume or environment variables. Let's leave it here and see others' ideas.

[nfrankel]

Instead of a Config Map, you could use a Secret