Fix new Sonar smells

Author: artembilan

spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBean.java

@@ -137,7 +137,7 @@ public void setStreamsConfiguration(Properties streamsConfig) {
 
 	@Nullable
 	public Properties getStreamsConfiguration() {
-		return this.properties;
+		return this.properties; // NOSONAR - inconsistent synchronization
 	}
 
 	public void setClientSupplier(KafkaClientSupplier clientSupplier) {
@@ -281,10 +281,4 @@ public synchronized boolean isRunning() {
 		return this.running;
 	}
 
-	private Properties propertiesFromConfigs(Map<String, Object> configs) {
-		Properties props = new Properties();
-		props.putAll(configs);
-		return props;
-	}
-
 }

spring-kafka/src/main/java/org/springframework/kafka/listener/AbstractMessageListenerContainer.java

@@ -451,7 +451,7 @@ public void stop(Runnable callback) {
 	 * @return the {@link ConsumerRebalanceListener} currently assigned to this container.
 	 */
 	protected final ConsumerRebalanceListener createSimpleLoggingConsumerRebalanceListener() {
-		return new ConsumerRebalanceListener() {
+		return new ConsumerRebalanceListener() { // NOSONAR - anonymous inner class length
 
 			@Override
 			public void onPartitionsRevoked(Collection<TopicPartition> partitions) {