Update app_flutter to match the latest dartfmt rules (#931)
Update app_flutter to match the latest dartfmt rules (#931)

* Update app_flutter to match the latest dartfmt rules

* add comments to enforce new dartfmt style rules on stable dartfmt

Co-authored-by: Christopher Fujino <f334d3eb554691c430f0050c059f31fda9baad85@gmail.com>
flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon,flutter/cocoon