As seen in the Cordova plugin (https://github.com/mjwheatley/cordova-plugin-android-fingerprint-auth) the isAvailable method returns an object that contains 3 parameters, {isAvailable:, isHardwareDetected, hasEnrolledFingerprints}.
If you do a console log on
this.androidFingerprintAuth.isAvailable()
.then(res => console.log(res)) //Outputs the Object {isAvailable: true, isHardwareDetected: true, hasEnrolledFingerprints: true}
.catch(err => console.error(err));
So we are getting the data, just need to make the interface expose it.