Make tpcEnable for client configurable through system property. (haze…

…lcast#25869)

Before this PR it was only configurable through the XML.

A system property provides a lot more flexibility and is very useful for
performance testing since the xml files don't need to be updated.

hazelcast/src/main/java/com/hazelcast/client/config/ClientTpcConfig.java

@@ -35,7 +35,8 @@
 @Beta
 public final class ClientTpcConfig {
 
-    private boolean enabled;
+    private boolean enabled = Boolean.parseBoolean(
+            System.getProperty("hazelcast.client.tpc.enabled", "false"));
 
     public ClientTpcConfig() {
     }

hazelcast/src/test/java/com/hazelcast/client/config/ClientTpcConfigTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2008-2023, Hazelcast, Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hazelcast.client.config;
+
+import com.hazelcast.test.HazelcastSerialClassRunner;
+import com.hazelcast.test.annotation.QuickTest;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Needs to run serially because it messes with system properties.
+ */
+@RunWith(HazelcastSerialClassRunner.class)
+@Category(QuickTest.class)
+public class ClientTpcConfigTest {
+
+    @Before
+    public void before() {
+        System.clearProperty("hazelcast.client.tpc.enabled");
+    }
+
+    @After
+    public void after() {
+        System.clearProperty("hazelcast.client.tpc.enabled");
+    }
+
+    @Test
+    public void test() {
+        ClientTpcConfig config = new ClientTpcConfig();
+        assertFalse(config.isEnabled());
+
+        System.setProperty("hazelcast.client.tpc.enabled", "true");
+        config = new ClientTpcConfig();
+        assertTrue(config.isEnabled());
+
+        System.setProperty("hazelcast.client.tpc.enabled", "false");
+        config = new ClientTpcConfig();
+        assertFalse(config.isEnabled());
+    }
+}