Hide toasts and drawers when tapping in overlays

Currently when a toast is showed in an overlay that is not scrollable
(e.g. editor with a short section), there's no way of getting rid of
the error toast that covers the "Keep editing" link.

Change-Id: I1188f29a98b22b8e3ab84ea5ed9d40b7572c7afa
Merge "Hide toasts and drawers when tapping in overlays"