Running a Dart / Flutter app does not upgrade DevTools tool windows to "connected" experience

[kenzieschmoll]

Repro steps:

1. Open a Flutter project in Android Studio.
2. Open the Flutter DevTools tool window.
3. Run the flutter app.
4. Observe that the Flutter DevTools tool window does not "upgrade" to a connected experience where DevTools is connected to the running app.

Hitting the refresh button does nothing.