MDEV-25769 : Galera test failure on galera_sr.GCF-627

Add wait_condition to wait until streaming log is empty.

mysql-test/suite/galera_sr/r/GCF-627.result

@@ -16,11 +16,9 @@ connect node_1a, 127.0.0.1, root, , test, $NODE_MYPORT_1;
 INSERT INTO t1 VALUES (2);
 ERROR 42S02: Table 'test.t1' doesn't exist
 connection node_1;
-SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log;
-COUNT(*) = 0
-1
+SELECT * FROM mysql.wsrep_streaming_log;
+node_uuid	trx_id	seqno	flags	frag
 connection node_2;
-SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log;
-COUNT(*) = 0
-1
+SELECT * FROM mysql.wsrep_streaming_log;
+node_uuid	trx_id	seqno	flags	frag
 DROP TABLE t2;

mysql-test/suite/galera_sr/t/GCF-627.test

@@ -22,9 +22,14 @@ COMMIT;
 INSERT INTO t1 VALUES (2);
 
 --connection node_1
-SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log;
+--let $wait_condition = SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log
+--source include/wait_condition.inc
+
+SELECT * FROM mysql.wsrep_streaming_log;
 
 --connection node_2
-SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log;
+--let $wait_condition = SELECT COUNT(*) = 0 FROM mysql.wsrep_streaming_log
+--source include/wait_condition.inc
+SELECT * FROM mysql.wsrep_streaming_log;
 
 DROP TABLE t2;