Fixing bug in StableMasterDisruptionIT.testRepeatedNullMasterRecognizedAsGreenIfMasterDoesNotKnowItIsUnstable() (#87519)

The test could wait up to 30 seconds for a master to step down. In that case, the start of the "null" master
could be 30 seconds ago, which put it outside of the range of the default acceptable time for there to
have been a master for the stability check. So the stability check returned RED since there was no master
in the last 30 seconds. This changes that setting to 60 seconds so that it is always picked up.

server/src/internalClusterTest/java/org/elasticsearch/discovery/StableMasterDisruptionIT.java

@@ -23,6 +23,7 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.set.Sets;
+import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.core.Tuple;
 import org.elasticsearch.health.GetHealthAction;
 import org.elasticsearch.health.HealthStatus;
@@ -424,6 +425,10 @@ public class StableMasterDisruptionIT extends ESIntegTestCase {
                 .put(LeaderChecker.LEADER_CHECK_TIMEOUT_SETTING.getKey(), "1s")
                 .put(Coordinator.PUBLISH_TIMEOUT_SETTING.getKey(), "1s")
                 .put(StableMasterHealthIndicatorService.NO_MASTER_TRANSITIONS_THRESHOLD_SETTING.getKey(), 1)
+                .put(
+                    StableMasterHealthIndicatorService.NODE_HAS_MASTER_LOOKUP_TIMEFRAME_SETTING.getKey(),
+                    new TimeValue(60, TimeUnit.SECONDS)
+                )
                 .build()
         );
         ensureStableCluster(3);

server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java

@@ -515,6 +515,7 @@ public final class ClusterSettings extends AbstractScopedSettings {
         DataTier.ENFORCE_DEFAULT_TIER_PREFERENCE_SETTING,
         StableMasterHealthIndicatorService.IDENTITY_CHANGES_THRESHOLD_SETTING,
         StableMasterHealthIndicatorService.NO_MASTER_TRANSITIONS_THRESHOLD_SETTING,
+        StableMasterHealthIndicatorService.NODE_HAS_MASTER_LOOKUP_TIMEFRAME_SETTING,
         MasterHistory.MAX_HISTORY_AGE_SETTING,
         ReadinessService.PORT
     );