Finalization OCC

[a-thaler]

Description When trying out the receivers the first time, I stumbled across these findings:

• [x] kymastatsreceiver: exclude "kyma" and "moduleTemplate" resource
• [x] kymastatsreceiver: add module_groups to example
• [ ] singletonreceivercreator: use current namespace for lease if available
• [x] example in kymastatsreceiver uses kubeConfig for auth, please change to serviceAccount
• [x] example in kymastatsreceiver seem to use wrong metric kyma.module.status.condition or wrong syntax {"level":"error","ts":1721644957.6690311,"caller":"singletonreceivercreator@v0.0.1/receiver.go:69","msg":"Failed to start subreceiver","kind":"receiver","name":"singleton_receiver_creator","data_type":"metrics","error":"failed to start wrapped receiver kymastats: failed to load \"kymastats\" subreceiver config: 1 error(s) decoding:\n\n* 'metrics' has invalid keys: kyma.module.status.condition","stacktrace":"github.com/kyma-project/opentelemetry-collector-components/receiver/singletonreceivercreator.(*singletonReceiverCreator).Start.func1\n\tgithub.com/kyma-project/opentelemetry-collector-components/receiver/singletonreceivercreator@v0.0.1/receiver.go:69"}
• [x] kymastatsreceiver: do not fail on missing "status" but print warning

[skhalash]

Identifying the current lease namespace in singletonreceivercreator is not a trivial task. We support three Kubernetes authentication types:

• serviceAccount: The current namespace can be identified using this method.
• kubeConfig: The current context can be read from the kubeconfig.
• none: Identification is not possible.

Additionally, the upstream module includes a tls auth type, which we did not adopt. Even if we had, identifying the current namespace would not be feasible in that case.

After a discussion with @a-thaler we decided to drop this feature and instead make lease namespace a required field.

[skhalash]

Since it's still unclear if we are able to generate generic metrics applicable for all Kyma modules, it was decided to remove module discovery in favor of a static configuration, instructing kymastatsreceiver to only generate metrics for the Telemetry module.