Randomise retention lease expiry time (#44067)

In today's test suite indices mostly use the default value of `12h` for the
`index.soft_deletes.retention_lease.period` setting, which in the context of
the test suite essentially means "never expires". In fact, the tests should all
behave correctly even if the lease period is much shorter; tests that rely on
leases not expiring should configure their indices appropriately.

This commit randomises the lease expiry time for those indices created during
tests which do not set a specific value for this setting.

test/framework/src/main/java/org/elasticsearch/test/ESIntegTestCase.java

@@ -169,9 +169,11 @@ import java.util.function.Function;
 import static org.elasticsearch.client.Requests.syncedFlushRequest;
 import static org.elasticsearch.cluster.metadata.IndexMetaData.SETTING_NUMBER_OF_REPLICAS;
 import static org.elasticsearch.cluster.metadata.IndexMetaData.SETTING_NUMBER_OF_SHARDS;
+import static org.elasticsearch.common.unit.TimeValue.timeValueMillis;
 import static org.elasticsearch.common.util.CollectionUtils.eagerPartition;
 import static org.elasticsearch.discovery.DiscoveryModule.DISCOVERY_SEED_PROVIDERS_SETTING;
 import static org.elasticsearch.discovery.SettingsBasedSeedHostsProvider.DISCOVERY_SEED_HOSTS_SETTING;
+import static org.elasticsearch.index.IndexSettings.INDEX_SOFT_DELETES_RETENTION_LEASE_PERIOD_SETTING;
 import static org.elasticsearch.index.query.QueryBuilders.matchAllQuery;
 import static org.elasticsearch.test.XContentTestUtils.convertToMap;
 import static org.elasticsearch.test.XContentTestUtils.differenceBetweenMapsIgnoringArrayOrder;
@@ -675,6 +677,10 @@ public abstract class ESIntegTestCase extends ESTestCase {
         if (randomBoolean()) {
             builder.put(IndexSettings.INDEX_SOFT_DELETES_RETENTION_OPERATIONS_SETTING.getKey(), between(0, 1000));
         }
+        if (randomBoolean()) {
+            builder.put(INDEX_SOFT_DELETES_RETENTION_LEASE_PERIOD_SETTING.getKey(), timeValueMillis(randomLongBetween(0, randomBoolean()
+                    ? 1000 : INDEX_SOFT_DELETES_RETENTION_LEASE_PERIOD_SETTING.get(Settings.EMPTY).millis())).getStringRep());
+        }
         return builder.build();
     }