code: async function showRationaleDialog(title: string, message: string): Promise<*> {
    let done;
    const result = new Promise(resolve => {
      done = resolve;
    });
  
    Alert.alert(
      title,
      message,
      [
        {
          text: 'OK',
          onPress: () => done()
        }
      ],
      { cancelable: false }
    );
  
    return result;
  }
docs: /* Private fucntion to create a dialog with an OK button
  This is because the RN rationale dialog has no buttons, so isn't obvious to dismiss
  NOTE: We always show this dialog, if cameraPermission not present