Fix modifier order in BytesStreamsTests

This commit fixes an issue with the ordering of modifiers on a static
nested class in BytesStreamsTests.

core/src/test/java/org/elasticsearch/common/io/stream/BytesStreamsTests.java

@@ -503,7 +503,7 @@ public class BytesStreamsTests extends ESTestCase {
         out.close();
     }
 
-    private static abstract class BaseNamedWriteable implements NamedWriteable {
+    private abstract static class BaseNamedWriteable implements NamedWriteable {
 
     }