code: public void revokePermission(UsbDevice device, String packageName) {
      List<UsbDevice> usbDevices = grantedPermissions.get(packageName);
      if (usbDevices != null) {
        usbDevices.remove(device);
      }
    }
docs: Revokes permission to a USB device granted to a package. This method does nothing if the
  package doesn't have permission to access the device.