[Best practice] CNF should not rely on local persistent storage for data retention

[taylor]

A CNF or more specifically containers within a K8s Workload Resource (aka CNF's microservices) may use local storage if available, but must not rely on it for persistent storage of data.

Local storage should be treated as ephemeral.

If the CNF's microservice using local storage restarts, the node reboots, or the microservice is rescheduled it should not FAIL if the data is no longer available on local storage. Eg. it should expect that local storage may not retain the data it stored there.