The rollup index name is null which suggests the test times out while waiting.

**Build scan:**
https://gradle-enterprise.elastic.co/s/au6yvyqh7t5da/tests/:x-pack:plugin:ilm:qa:multi-node:javaRestTest/org.elasticsearch.xpack.ilm.actions.DownsampleActionIT/testRollupIndex

**Reproduction line:**
```
./gradlew ':x-pack:plugin:ilm:qa:multi-node:javaRestTest' --tests "org.elasticsearch.xpack.ilm.actions.DownsampleActionIT.testRollupIndex" -Dtests.seed=87E7B73A4FA3E50A -Dtests.locale=pl-PL -Dtests.timezone=Asia/Qatar -Druntime.java=20
```

**Applicable branches:**
main

**Reproduces locally?:**
No

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.ilm.actions.DownsampleActionIT&tests.test=testRollupIndex

**Failure excerpt:**
```
java.lang.AssertionError: Cannot retrieve rollup index name

  at __randomizedtesting.SeedInfo.seed([87E7B73A4FA3E50A:61C3C66C26EFECC6]:0)
  at org.junit.Assert.fail(Assert.java:88)
  at org.junit.Assert.assertTrue(Assert.java:41)
  at org.junit.Assert.assertNotNull(Assert.java:712)
  at org.elasticsearch.xpack.ilm.actions.DownsampleActionIT.testRollupIndex(DownsampleActionIT.java:154)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
  at java.lang.reflect.Method.invoke(Method.java:578)
  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:1623)

```
x-pack/plugin/ilm/qa/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/ilm/actions/DownsampleActionIT.java
import org.elasticsearch.xpack.core.ilm.LifecycleAction;
import org.elasticsearch.xpack.core.ilm.LifecyclePolicy;
import org.elasticsearch.xpack.core.ilm.LifecycleSettings;
import org.elasticsearch.xpack.core.ilm.Phase;
import org.elasticsearch.xpack.core.ilm.PhaseCompleteStep;
import org.elasticsearch.xpack.core.ilm.RolloverAction;
import org.elasticsearch.xpack.core.rollup.ConfigTestHelpers;
import org.junit.Before;
import java.io.IOException;
import java.time.Instant;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.createIndexWithSettings;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.createNewSingletonPolicy;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.explainIndex;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.getOnlyIndexSettings;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.getStepKeyForIndex;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.index;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.rolloverMaxOneDocCondition;
import static org.elasticsearch.xpack.TimeSeriesRestDriver.updatePolicy;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.is;
public class DownsampleActionIT extends ESRestTestCase {
    private String index;
    private String policy;
    private String alias;
    private String dataStream;
    private static final String TEMPLATE = """