Polish "Disable auto-detection in tests that start Hazelcast"

See gh-31863

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastAutoConfigurationServerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.boot.autoconfigure.hazelcast;
 import java.util.Map;
 
 import com.hazelcast.config.Config;
+import com.hazelcast.config.JoinConfig;
 import com.hazelcast.config.QueueConfig;
 import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.HazelcastInstance;
@@ -130,8 +131,7 @@ class HazelcastAutoConfigurationServerTests {
 
 	@Test
 	void configInstanceWithName() {
-		Config config = new Config("my-test-instance");
-		config.getNetworkConfig().getJoin().getAutoDetectionConfig().setEnabled(false);
+		Config config = createTestConfig("my-test-instance");
 		HazelcastInstance existing = Hazelcast.newHazelcastInstance(config);
 		try {
 			this.contextRunner.withUserConfiguration(HazelcastConfigWithName.class)
@@ -165,6 +165,14 @@ class HazelcastAutoConfigurationServerTests {
 		});
 	}
 
+	private static Config createTestConfig(String instanceName) {
+		Config config = new Config(instanceName);
+		JoinConfig join = config.getNetworkConfig().getJoin();
+		join.getAutoDetectionConfig().setEnabled(false);
+		join.getMulticastConfig().setEnabled(false);
+		return config;
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class HazelcastConfigWithName {
 
@@ -180,8 +188,7 @@ class HazelcastAutoConfigurationServerTests {
 
 		@Bean
 		Config anotherHazelcastConfig() {
-			Config config = new Config();
-			config.getNetworkConfig().getJoin().getAutoDetectionConfig().setEnabled(false);
+			Config config = createTestConfig("another-test-instance");
 			config.addQueueConfig(new QueueConfig("another-queue"));
 			return config;
 		}

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-session-hazelcast/src/main/resources/hazelcast.xml

@@ -11,6 +11,7 @@
 
 	<network>
 		<join>
+			<auto-detection enabled="false"/>
 			<multicast enabled="false"/>
 		</join>
 	</network>