While working on the `unused-promise` Flow lint (in particular, "[web] Hide that InputState.sendTextMessage returns a Promise") I noticed that Flow was failing to typecheck the return value of these selectors.
Adding this cast fixed the issue, and things appear to be typechecked correctly now.
(@atul, this was the change that previously caused `minimallyEncoded` type errors for me, but no longer does after rebasing.)
Depends on D10167