public synchronized void setPartitionReplicaLag(RemoteReplicaInfo rinfo, long lag) {
    long pid = rinfo.getReplicaId().getPartitionId().getId();
    String rid = rinfo.getReplicaId().getDataNodeId().getHostname();
    metricMap.compute(pid, (k, v) -> v == null ? new AzureStorageContainerMetrics(pid).setPartitionReplicaLag(rid, lag)
        : v.setPartitionReplicaLag(rid, lag));
  }
Sets the lag of azure-container from ambry-partition.
We use a compare-set to guard against accidental multithreaded errors, although two threads will most likely
not be responsible for a single partition in VCR. A single thread handles all replicas of a partition.
However, we want to avoid any races between reader and writers.
Use min() as bootstrapping replicas can give a wrong picture and indicate a large lag even though the partition
is fully backed up in Azure.
@param rinfo RemoteReplicaInfo
@param lag Lag in bytes
ambry-cloud/src/main/java/com/github/ambry/cloud/azure/AzureStorageContainerMetricsCollector.java