Revert "Started looking for the dart plugin registrant at runtime  (#31418)" (#32162)
Revert "Started looking for the dart plugin registrant at runtime  (#31418)" (#32162)

This reverts commit e97c8016e398d91d414d298ae9ca87e735441476.
devoncarew/engine,flutter/engine,devoncarew/engine,flutter/engine,jason-simmons/flutter_engine,chinmaygarde/flutter_engine,chinmaygarde/flutter_engine,jason-simmons/flutter_engine,chinmaygarde/flutter_engine,rmacnak-google/engine,chinmaygarde/flutter_engine,flutter/engine,jason-simmons/flutter_engine,rmacnak-google/engine,devoncarew/engine,chinmaygarde/flutter_engine,devoncarew/engine,rmacnak-google/engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,flutter/engine,rmacnak-google/engine,jason-simmons/flutter_engine,rmacnak-google/engine,flutter/engine,flutter/engine,rmacnak-google/engine,chinmaygarde/flutter_engine,devoncarew/engine,flutter/engine,rmacnak-google/engine,devoncarew/engine,flutter/engine,devoncarew/engine,chinmaygarde/flutter_engine,jason-simmons/flutter_engine