fix(ci): Prevent workflow failures in relocated adk_team samples

Workflows failed because the gemini-2.5-pro model is not available for our projects and the CONTRIBUTING.md relative path resolved incorrectly after relocation. Updated the model to gemini-3.5-flash and adjusted the path resolver depth.

Change-Id: Iffc8a2b0044f3d73b0cb0b364db220d2bd055683