conversion_environment requirement for in-app conversion imports dropped, then bidding change cancelled

Google dropped the June 30, 2025 hard requirement for ClickConversion.conversion_environment on in-app conversions, instead planning (from September 30, 2025) to have bidding models rely on the field's presence. That bidding change was itself cancelled in October 2025.

Timeline: originally a required field from June 30, 2025; changed on May 27, 2025 to a gradual bidding-model change from September 30, 2025; the June 30 update removed that deadline; on October 8, 2025 Google confirmed the bidding enforcement would not be implemented. Setting conversion_environment remains recommended for cross-environment attribution and ad destination reporting.