We use `export default` begrudgingly here. Ideally we'd use just `export`, though this entire SDK expects things to be exported as a default. Instead of breaking everything, we'll sacrifice our export pattern for a smaller diff - a later commit can always do the default export -> regular export conversion.
Rooms which are already upgraded shouldn't be asked to upgrade. Additionally, this fixes a bug where the room upgrade dialog would stay open even after upgrading the room.
This lessens the warning for unstable-but-not-official versions while still communicating that the version is unstable. In the future, we may want to make this state dismissable.
