feat(helmchart): Extend helm chart to include automount toggle for service account

[vakaobr]

Reason for Change:

• Depending of the security controls in place on the cluster, service accounts may have the automountServiceAccountToken property set to false, but setting this to false introduces the need to set the property to true explicitly inside the deployment, in order to have the token/certs mounted to the pods.

Requirements

• squashed commits
• included documentation
• added unit tests and e2e tests (if applicable).

Issue Fixed:

Please answer the following questions with yes/no:

Does this change contain code from or inspired by another project? If so, did you notify the maintainers and provide attribution?

• yes
• no

Notes for Reviewers:

• In current state, when deploying the current chart to a cluster with policies to prevent service account automount, it fails. Since the pod do not mount the secret the pods fails to start with:

{"level":"error","timestamp":"2024-07-30T10:00:27.548370Z","logger":"controller-runtime.client.config","caller":"/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/client/config/config.go:133$config.loadConfig.func1","message":"unable to load in-cluster config","error":"open /var/run/secrets/kubernetes.io/serviceaccount/token: no such file or directory"}

[vakaobr]

@microsoft-github-policy-service agree

[vakaobr]

Hey @aramase @enj maybe you folks want to have a look on this one? Thanks :)

[aramase]

Thank you for the PR!

1. You need to update the helm chart generator here with the changes and then run make generate.
2. Also need to add the new variable in the helm chart readme with a description on what it means.