HDFS-17745. TestRouterMountTable should reset defaultNSEnable to true after each test method. (#7446). Contributed by hfutatzhanghb.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterMountTable.java

@@ -132,6 +132,7 @@ public class TestRouterMountTable {
           RemoveMountTableEntryRequest.newInstance(entry.getSourcePath());
       mountTableManager.removeMountTableEntry(req2);
     }
+    mountTable.setDefaultNSEnable(true);
   }
 
   @Test