Your module is nice already. But a little suggestion.
Instead of a module without any interface, you can make an UI and make an on/off switch which will enable or disable the function. Also, a widget can be implemented tapping on which will do the same function instead of power button. Because we use power button more frequently.
It will be like the following when module is enabled:
Touch the widget > next unlock will ask for Password/Pin/Pattern instead of fingerprint.
Lock the phone with power button will not invoke this function.
Your module is nice already. But a little suggestion.
Instead of a module without any interface, you can make an UI and make an on/off switch which will enable or disable the function. Also, a widget can be implemented tapping on which will do the same function instead of power button. Because we use power button more frequently.
It will be like the following when module is enabled: Touch the widget > next unlock will ask for Password/Pin/Pattern instead of fingerprint. Lock the phone with power button will not invoke this function.