Implement `onInit` and `onCheck` hooks in pre-generated Dart change detectors. This mirrors the changes made to the JIT change detector in c39c8ebcd056476728a5a56b8138a492850d7754.
Implement `onInit` and `onCheck` hooks in pre-generated Dart change detectors. This mirrors the changes made to the JIT change detector in c39c8ebcd056476728a5a56b8138a492850d7754.