Singleton beans use a JsonCreator with mode=PROPERTIES (#2351)

Singleton beans use a JsonCreator with mode=PROPERTIES

Author: carterkozak

changelog/@unreleased/pr-2351.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Singleton beans use a JsonCreator with mode=PROPERTIES
+  links:
+  - https://github.com/palantir/conjure-java/pull/2351

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();
     }