[Kubernetes] Pod name and worker index mismatch

[Michaelvll]

SkyPilot creates the pod with IDs in the pod name, but the ID does not match the id in the ssh config setup for the workers (also the ID that shows in the multi-node task). This creates confusion to our users.

For example:

In a big cluster (e.g. 16 node cluster), ssh-ing into worker 3 for example can land the user on pod 16, etc.

[dan-blanchard]

@Michaelvll I put up a PR to address this issue: #8037. Let me know what you think