Singleton beans use a JsonCreator with mode=PROPERTIES

See the discussion here:
FasterXML/jackson-databind#4688 (comment)

Ideally we can avoid deserialization failures for existing code,
but it's better to align our usage with the maintainers vision
either way :-)

Author: carterkozak

conjure-java-core/src/integrationInput/java/com/palantir/product/EmptyObjectExample.java

@@ -405,7 +405,7 @@ private static MethodSpec createStaticFactoryMethodForEmptyBean(ClassName object
         return MethodSpec.methodBuilder("of")
                 .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
                 .returns(objectClass)
-                .addAnnotation(ConjureAnnotations.delegatingJsonCreator())
+                .addAnnotation(ConjureAnnotations.propertiesJsonCreator())
                 .addCode("return $L;", SINGLETON_INSTANCE_NAME)
                 .build();
     }