Include mount_point in Kubernetes volume metricset

[eedugon]

Describe the enhancement:

This enhancement is slightly related to #39524, as the goal is to improve the monitoring of volumes.

Ideally it would be great to include the mount_point of kubernetes volumes, as all the volumes we collect are belonging to pods, and the pods are mounting the volumes in certain locations.

Anyway this request might be challenging, as internally the mount point is not part of the volume definition on the pod, it's included in the volumeMounts section. Hence I don't know how feasible this would be.

Including the mount points would give much better visibility to users monitoring their Kubernetes infrastructure.

Describe a specific use case for the enhancement or feature:

Kubernetes volumes and pods monitoring.

[elasticmachine]

Pinging @elastic/obs-ds-hosted-services (Team:obs-ds-hosted-services)