[Feature Request]: Add Google Gemini blocking thresholds

[pratham-darooka]

Is your feature request related to a problem? Please describe.

After https://github.com/microsoft/autogen/releases/tag/v0.2.25, it seems like Gemini works fine. However, in some cases the assistant’s prompts are blocked because of the Google Safety Settings.

Describe the solution you'd like

I plan to add thresholds and block levels in gemini.py

Additional context

No response

[pratham-darooka]

Created PR: #2410

[victordibia]

Fixed in #2429