CODE EXAMPLE FOR SHELL

Flutter plugin not installed; this adds Flutter specific functionality

Solution that worked for me:
  1. Just install plugins.
  		Studio>>File>Settings>Plugins>Browse Repositories
  2. Search for flutter.
  3. Tap on Install (a dialog will pop regarding dart dependency. click Yes).
  4. Once the installation is finished restart android studio.

If still not worked
  1. flutter channel dev
  2. flutter doctor -v