8345614: Improve AnnotationFormatError message for duplicate annotation interfaces

Backport-of: 7aa0cbc91d90493a3dae973cb8077cfa283c32b4

Author: liach

src/java.base/share/classes/sun/reflect/annotation/AnnotationParser.java

@@ -123,7 +123,7 @@ private static Map<Class<? extends Annotation>, Annotation> parseAnnotations2(
                 if (AnnotationType.getInstance(klass).retention() == RetentionPolicy.RUNTIME &&
                     result.put(klass, a) != null) {
                         throw new AnnotationFormatError(
-                            "Duplicate annotation for class: "+klass+": " + a);
+                            "Duplicate annotation " + klass + " in " + container);
             }
         }
         }