Background: Export the stub receiver

    package="org.lineageos.backgrounds">

    <application android:label="@string/app_name">

        <receiver android:name=".LineageBackgrounds">

        <receiver android:name=".StubReceiver"

                  android:exported="true">

            <intent-filter>

                <action android:name="com.android.launcher3.action.PARTNER_CUSTOMIZATION" />

            </intent-filter>

        </receiver>

    </application>

</manifest>