react-native-camera

fix(ios): fixed app crash on barcode detection without FirebaseMLVision (#2866)

Update the mode of the barcode detector only if it is a real detector.
Otherwise, the app will crash due to '-[BarcodeDetectorManagerMlkit setMode:queue:]:  unrecognized selector sent to instance'.

Co-authored-by: René Fischer <rene.fischer@zollsoft.de>