CSI plugins reporting duplicated volumes will crash the agent.

The CSI spec requires volumes to be uniquely identifiable by ID, and thus SLRP currently assumes that a ListVolumes call does not return duplicated volumes. However, if a SLRP uses a non-conforming CSI plugin that reports duplicated volumes, these volumes would corrupt the SLRP checkpoint and cause the agent to crash at the next reconciliation:

 F0829 07:13:55.171332 12721 provider.cpp:1089] Check failed: !checkpointedMap.contains(resource.disk().source().id())

MESOS-9254 introduces periodic reconciliation which make this problem much easier to manifest.