Don't need to assign meta to a new RS when standby master become active

I found this problem when I write ut for HBASE-20569. Now the master  finishActiveMasterInitialization introduce a new RecoverMetaProcedure(HBASE-18261) and it has a sub procedure AssignProcedure. AssignProcedure will skip assign a region when regions state is OPEN and server is online. But for the new regiog state node is created with state OFFLINE. So it will assign the meta to a new RS. And kill the old RS when old RS report to master. This will make the master initialization cost a long time. I will attatch a ut to show this. FYI stack