MINOR: Closing consumerGroupService resources in SaslClientsWithInvalidCredentialsTest (#8992)

Reviewers: Manikumar Reddy <manikumar.reddy@gmail.com>

core/src/test/scala/integration/kafka/api/SaslClientsWithInvalidCredentialsTest.scala

@@ -161,10 +161,11 @@ class SaslClientsWithInvalidCredentialsTest extends IntegrationTestHarness with
     val consumerGroupService: ConsumerGroupService = prepareConsumerGroupService
 
     val consumer = createConsumer()
-    consumer.subscribe(List(topic).asJava)
+    try {
+      consumer.subscribe(List(topic).asJava)
 
-    verifyAuthenticationException(consumerGroupService.listGroups())
-    consumerGroupService.close()
+      verifyAuthenticationException(consumerGroupService.listGroups())
+    } finally consumerGroupService.close()
   }
 
   @Test
@@ -173,19 +174,23 @@ class SaslClientsWithInvalidCredentialsTest extends IntegrationTestHarness with
     val consumerGroupService: ConsumerGroupService = prepareConsumerGroupService
 
     val consumer = createConsumer()
-    consumer.subscribe(List(topic).asJava)
+    try {
+      consumer.subscribe(List(topic).asJava)
 
-    verifyWithRetry(consumer.poll(Duration.ofMillis(1000)))
-    assertEquals(1, consumerGroupService.listConsumerGroups().size)
-    consumerGroupService.close()
+      verifyWithRetry(consumer.poll(Duration.ofMillis(1000)))
+      assertEquals(1, consumerGroupService.listConsumerGroups().size)
+    }
+    finally consumerGroupService.close()
   }
 
   private def prepareConsumerGroupService = {
     val propsFile = TestUtils.tempFile()
     val propsStream = Files.newOutputStream(propsFile.toPath)
-    propsStream.write("security.protocol=SASL_PLAINTEXT\n".getBytes())
-    propsStream.write(s"sasl.mechanism=$kafkaClientSaslMechanism".getBytes())
-    propsStream.close()
+    try {
+      propsStream.write("security.protocol=SASL_PLAINTEXT\n".getBytes())
+      propsStream.write(s"sasl.mechanism=$kafkaClientSaslMechanism".getBytes())
+    }
+    finally propsStream.close()
 
     val cgcArgs = Array("--bootstrap-server", brokerList,
                         "--describe",