fix: set automountServiceAccountToken to false when default service account is used

[wittdennis]

Description of the change

Sets automountServiceAccountToken: false when the default service account is used.

Benefits

This would lead to a more secure setup.

Possible drawbacks

None that come to my mind

Additional information

We follow the CIS Kubernetes Benchmark recommendations for a secure Kubernetes cluster setup.

As per point 5.1.5 Ensure that default service accounts are not actively used:
The default service account should not be used to ensure that rights granted to applications can be more easily audited and reviewed.

The suggested remediation is:
Create explicit service accounts wherever a Kubernetes workload requires specific access to the Kubernetes API server. Modify the configuration of each default service account to include this value:

automountServiceAccountToken: false

Checklist

• Chart version bumped in Chart.yaml according to semver.
• Variables are documented in the README.md

[tibuntu]

@dirsigler any chance this is going to be reviewed soon?

[dirsigler]

lgtm

[dirsigler]

Thank you very much for your patience and the contribution!