Currently, disableStreamableReplicaSetMonitor is a boolean, default to true.

In order to prepare for the addition of exhaust capabilities soon to come, change the disableReplicaSetMonitor server parameter to be
replicaSetMonitorMode: "scanning", "sdam" where scanning is the oldest ReplicaSetMonitor implementation, and sdam uses the new, sdam compliant ReplicaSetMonitor that does not support exhaust functionality.