test(kafka-binder): update retry expectations to align with corrected maxAttempts semantics

Updated Kafka binder tests to reflect the corrected semantics of `maxAttempts`.

Previously, tests assumed `maxAttempts` represented the number of retries,
leading to expectations of `maxAttempts + 1` total executions.

With the fix in AbstractBinder, `maxAttempts` now correctly represents the
total number of delivery attempts. As a result, test assertions have been
updated to match the new behavior.

No functional changes in Kafka binder logic; only test expectations updated.

Signed-off-by: vishwasio <im.vishwas.03@gmail.com>

Resolves #3186

Author: vishwasio

binders/kafka-binder/spring-cloud-stream-binder-kafka/src/test/java/org/springframework/cloud/stream/binder/kafka/KafkaBinderTests.java

@@ -1309,8 +1309,7 @@ else if (!HeaderMode.none.equals(headerMode)) {
 			boolean shouldHaveRetried = withRetry && !useConfiguredRetryableException;
 			assertThat(handler.getInvocationCount())
 					.isEqualTo(
-							shouldHaveRetried ? consumerProperties.getMaxAttempts() + 1 : 1);
-
+							shouldHaveRetried ? consumerProperties.getMaxAttempts() : 1);
 			assertThat(receivedMessage.getHeaders()
 					.get(KafkaMessageChannelBinder.X_ORIGINAL_TOPIC))
 							.isEqualTo(producerName.getBytes(StandardCharsets.UTF_8));
@@ -1422,7 +1421,7 @@ void defaultAutoCommitOnErrorWithDlq() throws Exception {
 				new String((byte[]) handledMessage.getPayload(), StandardCharsets.UTF_8))
 						.isEqualTo(testMessagePayload);
 		assertThat(handler.getInvocationCount())
-				.isEqualTo(consumerProperties.getMaxAttempts() + 1);
+				.isEqualTo(consumerProperties.getMaxAttempts());
 		binderBindUnbindLatency();
 		dlqConsumerBinding.unbind();
 		consumerBinding.unbind();
@@ -1484,7 +1483,7 @@ void retriesWithoutDlq() throws Exception {
 		// Since we don't have a DLQ, assert that we are invoking the handler exactly the same number of times
 		// as set in consumerProperties.maxAttempt and not the default set by Spring Kafka (10 times).
 		assertThat(handler.getInvocationCount())
-				.isEqualTo(consumerProperties.getMaxAttempts() + 1);
+				.isEqualTo(consumerProperties.getMaxAttempts());
 		binderBindUnbindLatency();
 		consumerBinding.unbind();
 		producerBinding.unbind();
@@ -1609,7 +1608,7 @@ void autoCommitOnErrorWhenManualAcknowledgement() throws Exception {
 				new String((byte[]) handledMessage.getPayload(), StandardCharsets.UTF_8))
 				.isEqualTo(testMessagePayload);
 		assertThat(handler.getInvocationCount())
-				.isEqualTo(consumerProperties.getMaxAttempts() + 1);
+				.isEqualTo(consumerProperties.getMaxAttempts());
 		binderBindUnbindLatency();
 		dlqConsumerBinding.unbind();
 		consumerBinding.unbind();
@@ -1689,7 +1688,7 @@ void configurableDlqName() throws Exception {
 				new String((byte[]) handledMessage.getPayload(), StandardCharsets.UTF_8))
 						.isEqualTo(testMessagePayload);
 		assertThat(handler.getInvocationCount())
-				.isEqualTo(consumerProperties.getMaxAttempts() + 1);
+				.isEqualTo(consumerProperties.getMaxAttempts());
 		binderBindUnbindLatency();
 		dlqConsumerBinding.unbind();
 		consumerBinding.unbind();