Steps to Reproduce

1. Run scaffold code sample flutter create --sample=material.Scaffold.drawer.1 ...
2. Open drawer
3. Press Escape key on keyboard

Expected results: Drawer should dismiss as DismissAction is documented to close drawers along with dialogs and popup menus

Actual results: Drawer is not dismissed. The handler for the action installed by ModalRoute does not work here because it is only enabled for barrier dismissible UIs.

Separately, I think there should be a PopAction that works for all types of routes, and a DismissOrPopAction that combines the two (emulating the Android back button). Will file a separate bug for that.