Only run dartfmt on stable.
Only run dartfmt on stable.

GitOrigin-RevId=3668a9027d19cc3007584649bd5defd4b85d7f22
PiperOrigin-RevId: 161996795

matanlurey/angular,kevmoo/angular,kevmoo/angular,chalin/angular2,angulardart/angular,chalin/angular2,matanlurey/angular,matanlurey/angular,angulardart/angular,angulardart/angular,kevmoo/angular,chalin/angular2