Description of problem:

When creating a CLF with dataModel as Otel with tuning configuration as empty, the default compression method 'snappy' is selected which is invalid for dataModel: Otel so the CLF errors out with below error

Error "Invalid value: "object": no such key: compression evaluating rule: 'snappy' compression cannot be used when data model is 'Otel'" for field "spec.outputs[0].lokiStack".

Empty tuning configuration is a valid configuration which should either assign compression as 'none' or 'gzip' in this case.

CLF spec:

spec:
  managementState: Managed
  outputs:
    - lokiStack:
        authentication:
          token:
            from: serviceAccount
        target:
          name: lokistack-dev
          namespace: openshift-logging
        tuning: {}
        dataModel: Otel
      name: logging-loki
      tls:
        ca:
          configMapName: openshift-service-ca.crt
          key: service-ca.crt
      type: lokiStack
  pipelines:
    - inputRefs:
        - application
        - infrastructure
        - audit
      name: logs-to-loki
      outputRefs:
        - logging-loki
  serviceAccount:
    name: my-loki-sa

Version-Release number of selected component (if applicable):

Logging 6.1.z

How reproducible:

Always

Steps to Reproduce:

1. Deploy cluster-logging.v6.1.1 
2. Create ClusterLogForwarder with dataModel as Otel and an empty tuning config.

Actual results:

CLF errors out with mentioned error as default compression method snappy is invalid for Otel.

Expected results:

CLF should be created with compression method as 'none' or 'gzip' for Otel

Additional info:

Apply the OTEL annotation on the CLF for this flow.

observability.openshift.io/tech-preview-otlp-output: enabled