[Zen2] Migrate no-master-block integration tests (#36502)

This change follows up on #36478 by migrating the affected integration tests to
use Zen2.

Author: DaveCTurner

modules/transport-netty4/src/test/java/org/elasticsearch/rest/discovery/Zen2RestApiIT.java

@@ -36,7 +36,6 @@
 import org.elasticsearch.common.settings.Settings.Builder;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.discovery.zen.ElectMasterService;
-import org.elasticsearch.gateway.GatewayService;
 import org.elasticsearch.http.HttpServerTransport;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.InternalTestCluster;
@@ -59,7 +58,6 @@ public class Zen2RestApiIT extends ESNetty4IntegTestCase {
     protected Settings nodeSettings(int nodeOrdinal) {
         final Builder builder = Settings.builder().put(super.nodeSettings(nodeOrdinal))
             .put(TestZenDiscovery.USE_ZEN2.getKey(), true)
-            .put(GatewayService.RECOVER_AFTER_MASTER_NODES_SETTING.getKey(), 1)
             .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), Integer.MAX_VALUE);
 
         if (nodeOrdinal == 0) {

server/src/main/java/org/elasticsearch/gateway/GatewayService.java

@@ -40,6 +40,7 @@
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.AbstractRunnable;
 import org.elasticsearch.discovery.Discovery;
+import org.elasticsearch.discovery.zen.ZenDiscovery;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.rest.RestStatus;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -115,9 +116,10 @@ public GatewayService(final Settings settings, final AllocationService allocatio
         // default the recover after master nodes to the minimum master nodes in the discovery
         if (RECOVER_AFTER_MASTER_NODES_SETTING.exists(settings)) {
             recoverAfterMasterNodes = RECOVER_AFTER_MASTER_NODES_SETTING.get(settings);
-        } else {
-            // TODO: change me once the minimum_master_nodes is changed too
+        } else if (discovery instanceof ZenDiscovery) {
             recoverAfterMasterNodes = settings.getAsInt("discovery.zen.minimum_master_nodes", -1);
+        } else {
+            recoverAfterMasterNodes = -1;
         }
 
         if (discovery instanceof Coordinator) {