Update FlowAggregator helm charts to support installing to a different namespace.

[andrew-su]

Describe the problem/challenge you have
I would like to deploy FlowAggregator to another namespace using helm.

Describe the solution you'd like
FlowAggregator deployable in different namespaces without resource conflicts.

Anything else you would like to add?

We also need to handle the situations where multiple FlowAggregators are deployed. It creates some cluster-wide resources and a RoleBinding in the kube-system namespace, so we need to ensure these resources are uniquely identified so they do not clobber each other on install.

We can take a look at https://github.com/kubernetes-sigs/external-dns/blob/031b6e4aedf212fe24a0865b2cea4ac628f712b0/charts/external-dns/templates/clusterrole.yaml#L5 for an example on how we can achieve this.

This came from a discussion #7641 (comment)