processor/k8sattributes: Add resource_attributes to metadata.yaml

This PR adds the resource attributes added by the k8sattributes processor to the metadata.yaml file in the resource_attributes group. Only the attributes which are added by default (see [documentation](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/v0.79.0/processor/k8sattributesprocessor#configuration)) are marked as enabled.

The generated config structs are not used, as resource attributes are exposed through a different configuration interface. This is noted in the metadata.yaml file.

Fixes: open-telemetry#23152.

processor/k8sattributesprocessor/internal/metadata/testdata/config.yaml

@@ -0,0 +1,89 @@
+default:
+all_set:
+  resource_attributes:
+    container.id:
+      enabled: true
+    container.image.name:
+      enabled: true
+    container.image.tag:
+      enabled: true
+    k8s.container.name:
+      enabled: true
+    k8s.cronjob.name:
+      enabled: true
+    k8s.daemonset.name:
+      enabled: true
+    k8s.daemonset.uid:
+      enabled: true
+    k8s.deployment.name:
+      enabled: true
+    k8s.deployment.uid:
+      enabled: true
+    k8s.job.name:
+      enabled: true
+    k8s.job.uid:
+      enabled: true
+    k8s.namespace.name:
+      enabled: true
+    k8s.node.name:
+      enabled: true
+    k8s.pod.hostname:
+      enabled: true
+    k8s.pod.name:
+      enabled: true
+    k8s.pod.start_time:
+      enabled: true
+    k8s.pod.uid:
+      enabled: true
+    k8s.replicaset.name:
+      enabled: true
+    k8s.replicaset.uid:
+      enabled: true
+    k8s.statefulset.name:
+      enabled: true
+    k8s.statefulset.uid:
+      enabled: true
+none_set:
+  resource_attributes:
+    container.id:
+      enabled: false
+    container.image.name:
+      enabled: false
+    container.image.tag:
+      enabled: false
+    k8s.container.name:
+      enabled: false
+    k8s.cronjob.name:
+      enabled: false
+    k8s.daemonset.name:
+      enabled: false
+    k8s.daemonset.uid:
+      enabled: false
+    k8s.deployment.name:
+      enabled: false
+    k8s.deployment.uid:
+      enabled: false
+    k8s.job.name:
+      enabled: false
+    k8s.job.uid:
+      enabled: false
+    k8s.namespace.name:
+      enabled: false
+    k8s.node.name:
+      enabled: false
+    k8s.pod.hostname:
+      enabled: false
+    k8s.pod.name:
+      enabled: false
+    k8s.pod.start_time:
+      enabled: false
+    k8s.pod.uid:
+      enabled: false
+    k8s.replicaset.name:
+      enabled: false
+    k8s.replicaset.uid:
+      enabled: false
+    k8s.statefulset.name:
+      enabled: false
+    k8s.statefulset.uid:
+      enabled: false

processor/k8sattributesprocessor/metadata.yaml

@@ -5,3 +5,90 @@ status:
   stability:
     beta: [logs, metrics, traces]
   distributions: [contrib, splunk, observiq, sumo]
+
+# resource attributes are exposed through a different configuration interface (extract::metadata).
+resource_attributes:
+  k8s.namespace.name:
+    description: The name of the namespace that the pod is running in.
+    type: string
+    enabled: true
+  k8s.pod.name:
+    description: The name of the Pod.
+    type: string
+    enabled: true
+  k8s.pod.uid:
+    description: The UID of the Pod.
+    type: string
+    enabled: true
+  k8s.pod.hostname:
+    description: The hostname of the Pod.
+    type: string
+    enabled: false
+  k8s.pod.start_time:
+    description: The start time of the Pod.
+    type: string
+    enabled: true
+  k8s.deployment.name:
+    description: The name of the Deployment.
+    type: string
+    enabled: true
+  k8s.deployment.uid:
+    description: The UID of the Deployment.
+    type: string
+    enabled: false
+  k8s.replicaset.name:
+    description: The name of the ReplicaSet.
+    type: string
+    enabled: false
+  k8s.replicaset.uid:
+    description: The UID of the ReplicaSet.
+    type: string
+    enabled: false
+  k8s.daemonset.name:
+    description: The name of the DaemonSet.
+    type: string
+    enabled: false
+  k8s.daemonset.uid:
+    description: The UID of the DaemonSet.
+    type: string
+    enabled: false
+  k8s.statefulset.name:
+    description: The name of the StatefulSet.
+    type: string
+    enabled: false
+  k8s.statefulset.uid:
+    description: The UID of the StatefulSet.
+    type: string
+    enabled: false
+  k8s.container.name:
+    description: The name of the Container in a Pod template.
+    type: string
+    enabled: false
+  k8s.job.name:
+    description: The name of the Job.
+    type: string
+    enabled: false
+  k8s.job.uid:
+    description: The UID of the Job.
+    type: string
+    enabled: false
+  k8s.cronjob.name:
+    description: The name of the CronJob.
+    type: string
+    enabled: false
+  k8s.node.name:
+    description: The name of the Node.
+    type: string
+    enabled: true
+  container.id:
+    description: Container ID. Usually a UUID, as for example used to identify Docker containers. The UUID might be abbreviated.
+    type: string
+    enabled: false
+  container.image.name:
+    description: Name of the image the container was built on.
+    type: string
+    enabled: false
+  container.image.tag:
+    description: Container image tag.
+    type: string
+    enabled: false