updateApp
Updates the app to the release that the last checkForNewRelease returned. Collecting the flow starts the update; it emits the update's progress, completes when the update has, and throws the FirebaseAppDistributionException the update failed with (AppDistributionExceptionStatus.UPDATE_NOT_AVAILABLE without a new release). Cancelling the collection does not cancel the update. On iOS it emits nothing: the release's download link is opened, and iOS asks the tester to install it.