@VisibleForTesting
  ConcurrentHashMap<SamzaResource, Container> getAllocatedResources() {
    return allocatedResources;
  }
Handles container started call back for a yarn container.
updates the YarnAppState's pendingProcessors and runningProcessors
and also invokes clusterManagerCallback.s stream processor launch success
@param containerId yarn container id which has started
samza-yarn/src/main/java/org/apache/samza/job/yarn/YarnClusterResourceManager.java