set service_name label for podLogs

[rlankfo]

This PR sets service_name, service_namespace, deployment_environment, and deployment_environment_name labels on Loki pod logs. This works when sent to loki destinations. I'll follow this PR up with updates for pod logs sent to OTLP destinations.

The labels are set according to the following rules:

• service_name label set by taking the first non-empty value from these Kubernetes metadata fields (in order): the pod annotation resource.opentelemetry.io/service.name, the pod label app.kubernetes.io/name, the pod’s name, or the container’s name.
• service_namespace set by resource.opentelemetry.io/service.namespace pod annotation.
• deployment_environment set by resource.opentelemetry.io/deployment.environment pod annotation.
• deployment_environment_name set by resource.opentelemetry.io/deployment.environment.name pod annotation.

If not set, Loki will attempt to set a default value according to these rules: https://grafana.com/docs/loki/latest/get-started/labels/#default-labels-for-all-users

[petewall]

LGTM. Run make build inside charts/k8s-monitoring to update the generated files.