Allow changing automountServiceAccountToken in the PodSpec

[vidarno]

Welcome!

• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've searched similar issues on the Traefik community forum and didn't find any.

What did you expect to see?

There is no way to set automountServiceAccountToken in the current helm chart.

automountServiceAccountToken is set to false in the actual service account definition, but in environments that have policies that require automountServiceAccountToken to be false in the actual Podspec this isn't good enough.

Ideally the same value would change automountServiceAccountToken in both the service account definition and in the podspec, but since they are respectively true and false by default this would effectively change the default behaviour if both were set by this one value so I suggest to only have this value control the attribute in the podspec and not both.

I am ready to provide a PR that provides this feature. It passes the tests and has updated the schema.