Find a way to obtain the AWS region without listing pods and nodes

[simonmarty]

For listing Pods and Nodes, it looks like thats only done for getting the AWS region. It'd be great if this could be provided by a Helm Chart environment variable in the short term. Longer term, if/when kubernetes/kubernetes#40610, that could just be injected into the pod without any user input.

Its worth noting that Kubelet today has permissions to list all pods (but not nodes), but this permission is going to be restricted in future versions of Kubernetes to only allow a node to list the pods running on it.