Gen AI with structured output - `propertyOrdering` in Python vs. Java implementations

Hi, when using gen AI with schema-constrained output, I've noticed in [`google/genai/_transformers.py`](https://github.com/googleapis/python-genai/blob/ccbc6c58bf872885cfc0a453325060340e415f34/google/genai/_transformers.py#L817), there's explicit handling of `propertyOrdering` (aka. `property_ordering`), while it seems that this is not the case in the Java implementation.

In the Python implementation the logic for including it is fairly simple: if `propertyOrdering` is missing, add it:
```py
if (
len(properties.items()) > 1
and order_properties # True by default
and 'propertyOrdering' not in schema
):
schema['property_ordering'] = list(properties.keys())
```

I wouldn't bring this up if it didn't actually result in AI returning different, and _**better**_ responses with it, vs. without it. Specifically, in my Java app, with the exact same prompt and basic schema (without explicitly setting `propertyOrdering`), AI consistently returns fewer fields than it does when invoked via the Python app.

Now I've noticed this field is labeled as non-standard, at least in v1.51.0, which I have locally:
```java
/**
* Setter for propertyOrdering.
*
*

propertyOrdering: Optional. Order of properties displayed or used where order matters.
* This is not a standard field in OpenAPI specification, but can be used to control the order
* of properties.
*/
```

Despite that, I've now added `propertyOrdering` to my schema (in Java). (Note, I have Vertex AI set to `true` in both cases, if that makes a difference.)

Is there any general information on this? In particular, is `propertyOrdering` expected to have an effect on structured output generation in Vertex AI, and should the Java implementation also be adding it automatically when it isn't explicitly provided?

Thanks.