Updated to compile with current latest usb-serial-for-android

Latest updates in the `usb-serial-for-android` removed the `setBaudRate` method in `UsbDriver`s, as well as deprecated `acquire` method in `UsbSerialProber` in favor of `findFirstDevice`.

This change, therefore, updates the `ArduinoFirmata-Android` implementation in order to fix compilation issues (1 error, 1 warning) with current latest `usb-serial-for-android`.