Gemini 2.0 Flash and 2.5 Flash structured output value repetition and missing fields

This is a known issue with [Controlled Generation](https://cloud.google.com/vertex-ai/generative-ai/docs/samples/generativeaionvertexai-gemini-controlled-generation-response-schema-2) and the Flash 2.0 models. It can affect the use of Flash 2.0 in extraction tasks, particularly involving repetitive token patterns.

For more details, refer to this similar issue:
[google-gemini/cookbook Issue #449](https://github.com/google-gemini/cookbook/issues/449)