Add k8s.node.system_container.* metrics

[PlateauGao]

Fixes #3531

Changes

Add k8s.node.system_container.* metrics and a self describing attribute k8s.node.system_container.name to capture node-level system daemon metrics." Please refer to the issue for detailed proposal

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Merge requirement checklist

• [x ] CONTRIBUTING.md guidelines followed.
• [ x] Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• [ x] Links to the prototypes or existing instrumentations (when adding or changing conventions)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: PlateauGao / name: Yuan Gao (06d3f65, 5085758, 5ea15ad, 6ee1394, a971636, c89b100, cff7d7e)

[PlateauGao]

Hi @dashpole , I wonder if you could please take another look at this PR? Thanks!

[jinja2]

k8s.node.system_container.name is only unique within a node (every node reports "kubelet", etc.), so an additional k8s.node.name/uid is needed to fully identify the system container. Would adding k8s.node to entity_associations on these metrics help make that dependency clearer? Not sure if we've discussed how to handle identity that depends on a parent entity in conventions yet

[jinja2]

@open-telemetry/semconv-k8s-approvers any thoughts on this?

[dashpole]

+1 to adding it.

[ChrsMark]

I think this should be handled by Entity Relationships once https://github.com/open-telemetry/opentelemetry-specification/pull/4836/changes#diff-ad0266d8d6589d7477414924c759cbaedfc425f6926c31c972eb138ed9cf8d88R179 is in. @dmitryax WDYT?

[PlateauGao]

Hi @ChrsMark, I wonder what the process would be? I wonder if we need to wait for an approver and maintainer? Or I can try to reach out to one maintainer

[PlateauGao]

Hi @jinja2, I wonder if you could please take another took and let me know if there is any other question? I think I need to have all comments resolved to get maintainer approval. Thanks!