[flutter_tool] enable single widget reload optimization by default on dev (#66995)
[flutter_tool] enable single widget reload optimization by default on dev (#66995)

Continued gradual rollout - dev is not that much riskier than master but will give much more data
flutter/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,cbracken/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,flutter/flutter,cbracken/flutter,cbracken/flutter,tvolkert/flutter,tvolkert/flutter,cbracken/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,cbracken/flutter