fix: Make serviceAccount.name and serviceAccount.create work

[lfrancke]

Same fix as stackabletech/hive-operator#742 please read there for details.

Fixing this here before I move the rest to operator templating because when we fix the _helpers.tpl and serviceaccount.yaml in templating they will be merged here and suddenly potentially make the whole create and name stuff actually work but those non-templated two files will still refer to the old SA which now doesn't exist and the pod won't start.

In other words: Currently it's ignored (broken). If we don't fix it here first pods might not start. So we fix it here first, then do templating.

secret-operator has the same two workloads and needs the same fix.

[dervoeti]

One thing is still a bit off, maybe we could also fix this while we're at it:
serviceaccount.yaml wraps both the ServiceAccount and the ClusterRoleBinding in {{ if .Values.serviceAccount.create }}, so with create=false no binding is rendered:

helm template foo ./deploy/helm/listener-operator --set serviceAccount.create=false --set serviceAccount.name=my-sa | grep '^kind:'
kind: StorageClass
kind: ClusterRole
kind: DaemonSet
kind: Deployment
kind: CSIDriver

So the pods now run as my-sa, but we don't grant it any permissions (the user has to provide the ClusterRoleBinding as well), while roles.yaml renders the ClusterRole unconditionally. Gating only the ClusterRoleBinding on serviceAccount.create seems unintentional.
I'd suggest we move the ClusterRoleBinding out of the if create block (or rename the whole flag to something like rbac.create and gate all three items behind it).

[lfrancke]

Ah yes. I saw this over in Hive as well and wondered if there is a reason for that. "Over there" I documented it assuming I didn't know enough about Kubernetes.

But yes: Happy to change it. I would suggest though to not do that in this PR but merge this and secret and then fix it for all of the operators via operator-templating.

[lfrancke]

What that means is I need to fix the docs for the value schema in Hive but that's not a problem

[lfrancke]

I created a templating PR with more explanation: stackabletech/operator-templating#637