<NME> PreferenceSystemFragment.java
<BEF> ADDFILE
<MSG> Add all Fragment Java classes and use them in the fragments

<DFF> @@ -0,0 +1,14 @@
+package cgeo.geocaching.settings.fragments;
+
+import cgeo.geocaching.R;
+
+import android.os.Bundle;
+
+import androidx.preference.PreferenceFragmentCompat;
+
+public class PreferenceSystemFragment extends PreferenceFragmentCompat {
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        setPreferencesFromResource(R.xml.preferences_system, rootKey);
+    }
+}

Add all Fragment Java classes and use them in the fragments