session-android/res/xml/preferences_storage.xml

<?xml version="1.0" encoding="utf-8"?>

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <org.thoughtcrime.securesms.components.SwitchPreferenceCompat
                        android:defaultValue="false"
                        android:key="pref_trim_threads"
                        android:summary="@string/preferences__automatically_delete_older_messages_once_a_conversation_thread_exceeds_a_specified_length"
                        android:title="@string/preferences__delete_old_messages" />

    <EditTextPreference android:defaultValue="500"
                        android:key="pref_trim_length"
                        android:title="@string/preferences__conversation_length_limit"
                        android:inputType="number"
                        android:dependency="pref_trim_threads" />

    <Preference android:key="pref_trim_now"
                android:title="@string/preferences__trim_all_threads_now"
                android:summary="@string/preferences__scan_through_all_conversation_threads_and_enforce_conversation_length_limits"
                android:dependency="pref_trim_threads" />

</PreferenceScreen>