Fix test

Author: acogoluegnes

src/test/java/com/rabbitmq/stream/impl/StreamEnvironmentTest.java

@@ -703,7 +703,7 @@ void streamExistsMetadataDataFallback(boolean lazyInit) {
         cp ->
             new Client(cp) {
               @Override
-              StreamStatsResponse streamStats(String stream) {
+              public StreamStatsResponse streamStats(String stream) {
                 throw new UnsupportedOperationException();
               }