Add explicit <Null> type to const list literal.
Add explicit <Null> type to const list literal.

The analyzer should really be able to infer this, but right now it isn't.

PiperOrigin-RevId: 241947200

angulardart/angular,angulardart/angular,matanlurey/angular,matanlurey/angular,matanlurey/angular,angulardart/angular