Log improvements in NodeStatusUpdaterImpl

if (LOG.isDebugEnabled()) {
          LOG.debug("The cache log aggregation status size:"
              + logAggregationReports.size());
 }

LOG.info("Sending out " + containerStatuses.size()
      + " NM container statuses: " + containerStatuses);

if (LOG.isDebugEnabled()) {
      LOG.debug("Sending out " + containerStatuses.size()
          + " container statuses: " + containerStatuses);
}