ring-android/app/src/main/res/xml/preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <PreferenceCategory android:title="Network">
        <android.support.v14.preference.SwitchPreference
            android:key="pref_mobileData"
            android:title="Mobile data"
            android:summary="Allow Ring on 3G/LTE networks additionally to Wi-Fi"
            android:defaultValue="false"
            android:icon="@drawable/ic_perm_data_setting_black_24dp"/>
    </PreferenceCategory>

    <PreferenceCategory android:title="Contacts">
        <android.support.v14.preference.SwitchPreference
            android:key="pref_systemContacts"
            android:title="Use system contacts"
            android:summary="Use system contacts to show caller details."
            android:defaultValue="true"
            android:icon="@drawable/ic_group_black_24dp"/>

    </PreferenceCategory>

</PreferenceScreen>