space quota usage is calculated almost double then actual usage in case of Split /Merge of region

space quota usage is calculated double for some time because it is considering the usage of the parent region report received earlier. This is normal behaviour because hbase.master.quotas.region.report.retention.millis is set as 10 minutes.It's not calculating the usage from the store files, it's taking the usage from the earlier report send to the master by the parent region server till 10 minutes.

So after 10 minutes, it stops considering the earlier region report and quota is not violated