TestRMDelegationTokens#testRMDTMasterKeyStateOnRollingMasterKey is failing intermittently

java.lang.AssertionError: null
at org.junit.Assert.fail(Assert.java:92)
at org.junit.Assert.assertTrue(Assert.java:43)
at org.junit.Assert.assertTrue(Assert.java:54)
at org.apache.hadoop.yarn.server.resourcemanager.security.TestRMDelegationTokens.testRMDTMasterKeyStateOnRollingMasterKey(TestRMDelegationTokens.java:117)