Correctly enable/disable the fingerprint option in the intro

app/src/main/java/me/impy/aegis/ui/slides/CustomAuthenticationSlide.java

@@ -8,10 +8,8 @@ import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.ArrayAdapter;
 import android.widget.RadioButton;
 import android.widget.RadioGroup;
-import android.widget.Spinner;
 import android.widget.TextView;
 
 import com.github.paolorotolo.appintro.ISlidePolicy;
@@ -25,7 +23,6 @@ public class CustomAuthenticationSlide extends Fragment implements ISlidePolicy,
     public static final int CRYPT_TYPE_PASS = 2;
     public static final int CRYPT_TYPE_FINGER = 3;
 
-    private Spinner _authenticationSpinner;
     private RadioGroup _buttonGroup;
     private int _bgColor;
 
@@ -36,13 +33,13 @@ public class CustomAuthenticationSlide extends Fragment implements ISlidePolicy,
         _buttonGroup.setOnCheckedChangeListener(this);
         onCheckedChanged(_buttonGroup, _buttonGroup.getCheckedRadioButtonId());
 
-        // only show the fingerprint option if the api version is new enough, permission is granted and a scanner is found
+        // only enable the fingerprint option if the api version is new enough, permission is granted and a scanner is found
         FingerprintManager manager = FingerprintHelper.getManager(getContext());
         if (manager != null) {
             RadioButton button = view.findViewById(R.id.rb_fingerprint);
             TextView text = view.findViewById(R.id.text_rb_fingerprint);
-            button.setEnabled(false);
-            text.setEnabled(false);
+            button.setEnabled(true);
+            text.setEnabled(true);
         }
 
         view.findViewById(R.id.main).setBackgroundColor(_bgColor);

app/src/main/res/layout/fragment_authentication_slide.xml

@@ -72,6 +72,7 @@
 
             <RadioButton
                 android:id="@+id/rb_fingerprint"
+                android:enabled="false"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:text="@string/authentication_method_fingerprint"
@@ -80,6 +81,7 @@
 
             <TextView
                 android:id="@+id/text_rb_fingerprint"
+                android:enabled="false"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_marginStart="32dp"