chore: Helm chart option to set POD container name

[udhos]

Fixes #7383

Description

Helm chart option to set POD container name.

Several of our observability tools rely on POD container name and "controller" is too much generic.

This change adds this option to values.yaml:

controller:
  # -- Distinguishing container name (containerName: karpenter-controller).
  containerName: controller

How was this change tested?

Using "helm template" to check it defaults to current setting (controller) and allows defining a new container name.

Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: #
• No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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