**Build scan:**
https://gradle-enterprise.elastic.co/s/gtccrq5lmqhy4/tests/:modules:data-streams:test/org.elasticsearch.datastreams.lifecycle.action.DataStreamLifecycleStatsResponseTests/testXContentSerialization


**Reproduction line:**
```
./gradlew ':modules:data-streams:test' --tests "org.elasticsearch.datastreams.lifecycle.action.DataStreamLifecycleStatsResponseTests.testXContentSerialization" -Dtests.seed=9553CDE988C341F8 -Dtests.locale=hi-IN -Dtests.timezone=Asia/Irkutsk -Druntime.java=21
```

**Applicable branches:**
main

**Reproduces locally?:**
Didn't try

**Failure history:**
https://es-delivery-stats.elastic.dev/app/dashboards#/view/dcec9e60-72ac-11ee-8f39-55975ded9e63?_g=(refreshInterval:(pause:!t,value:60000),time:(from:now-7d%2Fd,to:now))&_a=(controlGroupInput:(chainingSystem:HIERARCHICAL,controlStyle:twoLine,ignoreParentSettings:(ignoreFilters:!f,ignoreQuery:!f,ignoreTimerange:!f,ignoreValidations:!t),panels:('0c0c9cb8-ccd2-45c6-9b13-96bac4abc542':(explicitInput:(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,enhancements:(),fieldName:task.keyword,grow:!t,id:'0c0c9cb8-ccd2-45c6-9b13-96bac4abc542',searchTechnique:wildcard,selectedOptions:!(),singleSelect:!t,title:'Gradle%20Task',width:medium),grow:!t,order:0,type:optionsListControl,width:small),'144933da-5c1b-4257-a969-7f43455a7901':(explicitInput:(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,enhancements:(),fieldName:name.keyword,grow:!t,id:'144933da-5c1b-4257-a969-7f43455a7901',searchTechnique:wildcard,selectedOptions:!('testXContentSerialization'),title:Test,width:medium),grow:!t,order:2,type:optionsListControl,width:medium),'4e6ad9d6-6fdc-4fcc-bf1a-aa6ca79e0850':(explicitInput:(dataViewId:fbbdc689-be23-4b3d-8057-aa402e9ed0c5,enhancements:(),fieldName:className.keyword,grow:!t,id:'4e6ad9d6-6fdc-4fcc-bf1a-aa6ca79e0850',searchTechnique:wildcard,selectedOptions:!('org.elasticsearch.datastreams.lifecycle.action.DataStreamLifecycleStatsResponseTests'),title:Suite,width:medium),grow:!t,order:1,type:optionsListControl,width:medium))))


**Failure excerpt:**
```
java.lang.NullPointerException: Cannot invoke "java.lang.Long.intValue()" because the return value of "org.elasticsearch.datastreams.lifecycle.action.GetDataStreamLifecycleStatsAction$Response.getTimeBetweenStarts()" is null

  at __randomizedtesting.SeedInfo.seed([9553CDE988C341F8:4D6B387669D1DCC3]:0)
  at org.elasticsearch.datastreams.lifecycle.action.DataStreamLifecycleStatsResponseTests.testXContentSerialization(DataStreamLifecycleStatsResponseTests.java:124)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.lang.reflect.Method.invoke(Method.java:580)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:48)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:1583)

```
modules/data-streams/src/test/java/org/elasticsearch/datastreams/lifecycle/action/DataStreamLifecycleStatsResponseTests.java
assertThat(
                xContentMap.get("time_between_starts"),
                is(TimeValue.timeValueMillis(testInstance.getTimeBetweenStarts()).toHumanReadableString(2))
            );
            assertThat(xContentMap.get("data_stream_count"), is(testInstance.getDataStreamStats().size()));
            List<Map<String, Object>> dataStreams = (List<Map<String, Object>>) xContentMap.get("data_streams");
            if (testInstance.getDataStreamStats().isEmpty()) {
                assertThat(dataStreams.isEmpty(), is(true));
            } else {
                assertThat(dataStreams.size(), is(testInstance.getDataStreamStats().size()));
                for (int i = 0; i < dataStreams.size(); i++) {
                    assertThat(dataStreams.get(i).get("name"), is(testInstance.getDataStreamStats().get(i).dataStreamName()));
                    assertThat(
                        dataStreams.get(i).get("backing_indices_in_total"),
                        is(testInstance.getDataStreamStats().get(i).backingIndicesInTotal())
                    );
                    assertThat(
                        dataStreams.get(i).get("backing_indices_in_error"),
                        is(testInstance.getDataStreamStats().get(i).backingIndicesInError())
                    );
                }
            }
        }
    }
    @Override
    protected Writeable.Reader<GetDataStreamLifecycleStatsAction.Response> instanceReader() {
        return GetDataStreamLifecycleStatsAction.Response::new;
    }
}