[Bug][http-client-java] azure-json serialization, constant property in parent class cannot be accessed from child class

[XiaofeiCao]

Describe the bug

unbranded generated code: joseharriaga/openai-in-typespec@25c0126

tsp source: https://github.com/joseharriaga/openai-in-typespec/blob/610b77e85f60de6f7a1dfc7276e69fecddbc09ad/.typespec/fine-tuning/models.tsp#L328-L329
base model: https://github.com/joseharriaga/openai-in-typespec/blob/610b77e85f60de6f7a1dfc7276e69fecddbc09ad/.typespec/chat/models.tsp#L634

Current thought:

1. This property should be package-private, since all models are in the same package(no models-sub-packages configuration)
2. Access through getter?

Reproduction

see above

Checklist

• Follow our Code of Conduct
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.

[weidongxu-microsoft]

Seems we can treat it just the same way as a read-only property (duplicate it in subclass?).

[weidongxu-microsoft]

Or do we need to generate the @Override public String getRole() in subclass? If we don't generate it, seems the problem gone?

[XiaofeiCao]

Cause: base model is polymorphic child model. Sub model is this child model's child, but with no @discriminator defined.
Our codegen logic is based on the assumption that all models in the polymorphic hierarchy define their discriminator property.
This model breaks this assumption.
From their use case, they don't need this model and can always use parent model instead: https://github.com/joseharriaga/openai-in-typespec/blob/610b77e85f60de6f7a1dfc7276e69fecddbc09ad/.typespec/fine-tuning/models.tsp#L338