[tidb] Checkpoint is not updated long after a task has been running (#1686)

Co-authored-by: wangxiaojing <wangxiaojing@lixiang.com>

flink-connector-tidb-cdc/src/main/java/com/ververica/cdc/connectors/tidb/TiKVRichParallelSourceFunction.java

@@ -243,7 +243,7 @@ public class TiKVRichParallelSourceFunction<T> extends RichParallelSourceFunctio
                 }
                 handleRow(row);
             }
-            resolvedTs = cdcClient.getMinResolvedTs();
+            resolvedTs = cdcClient.getMaxResolvedTs();
             if (commits.size() > 0) {
                 flushRows(resolvedTs);
             }