@Override
    public int getNormalizerTargetRegionCount() {
      return getOrDefault(NORMALIZER_TARGET_REGION_COUNT_KEY, Integer::valueOf,
        Integer.valueOf(-1));
    }
Check if there is the target region count. If so, the normalize plan will be calculated based
on the target region count.
@return target region count after normalize done
hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java