HDFS-16106. Fix flaky unit test TestDFSShell (#3168)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSShell.java

@@ -117,7 +117,7 @@ public class TestDFSShell {
         GenericTestUtils.getTestDir("TestDFSShell").getAbsolutePath());
     conf.setBoolean(DFSConfigKeys.DFS_NAMENODE_XATTRS_ENABLED_KEY, true);
     conf.setBoolean(DFSConfigKeys.DFS_NAMENODE_ACLS_ENABLED_KEY, true);
-    conf.setLong(DFSConfigKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY, 1000);
+    conf.setLong(DFSConfigKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY, 120000);
 
     miniCluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
     miniCluster.waitActive();