acceptQRScanConfirmation method
call this to confirm that your other device has shown a shield and is in
done state.
Implementation
Future<void> acceptQRScanConfirmation() async {
  if (_method is _KeyVerificationMethodQRReciprocate &&
      state == KeyVerificationState.confirmQRScan) {
    await (_method as _KeyVerificationMethodQRReciprocate)
        .acceptQRScanConfirmation();
  }
}