AndroidAPS/app/src/main/res/xml/pref_maintenance.xml

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

    <PreferenceCategory
        android:key="@string/key_maintenance_settings"
        android:title="@string/maintenance_settings"
        app:initialExpandedChildrenCount="0">

        <info.nightscout.androidaps.utils.textValidator.ValidatingEditTextPreference
            android:defaultValue="logs@androidaps.org"
            android:dialogMessage="@string/maintenance_email"
            android:inputType="textEmailAddress"
            android:key="@string/key_maintenance_logs_email"
            android:selectAllOnFocus="true"
            android:title="@string/maintenance_email"
            validate:testType="email"/>

        <info.nightscout.androidaps.utils.textValidator.ValidatingEditTextPreference
            android:defaultValue="2"
            android:inputType="number"
            android:key="@string/key_maintenance_logs_amount"
            android:title="@string/maintenance_amount"
            validate:maxNumber="10"
            validate:minNumber="1"
            validate:testType="numericRange"/>

    </PreferenceCategory>

</androidx.preference.PreferenceScreen>