How to specify to not allow any data backup with android:dataExtractionRules?

My current Android application targets 12 and higher.

I do not want to allow backup of any type and currently have these manifest settings:

android:allowBackup="false"
android:fullBackupContent="false"

However the android:allowBackup="false" setting gives the following warning now:

The attribute android:allowBackup is deprecated from Android 12 and higher and may be removed in future versions. Consider adding the attribute android:dataExtractionRules specifying an @xml resource which configures cloud backups and device transfers on Android 12 and higher.

I've looked at the examples for android:dataExtractionRules xml and none of them show how to configure the equivalent of allowBackup="false".

What am I missing?

Is it possible to achieve allowBackup="false" with the use of android:dataExtractionRules xml?

Solution

Add dataExtractionRules attribute to your AndroidManifest.xml file with a reference to data_extraction_rules.xml file:

<application
    android:allowBackup="false"
    android:fullBackupContent="false"
    android:dataExtractionRules="@xml/data_extraction_rules"
    ...>

Then, exclude all possible domains for cloud backups and d2d transfers, update or create a file app/src/main/res/xml/data_extraction_rules.xml:

<?xml version="1.0" encoding="utf-8"?>
<data-extraction-rules>
    <cloud-backup>
        <exclude domain="root" />
        <exclude domain="file" />
        <exclude domain="database" />
        <exclude domain="sharedpref" />
        <exclude domain="external" />
    </cloud-backup>
    <device-transfer>
        <exclude domain="root" />
        <exclude domain="file" />
        <exclude domain="database" />
        <exclude domain="sharedpref" />
        <exclude domain="external" />
    </device-transfer>
</data-extraction-rules>

The dataExtractionRules attribute is available for API 31 (Android 12) and higher. Keep allowBackup and fullBackupContent attributes for Android versions before API 31.

Note to maybe silence "Attribute dataExtractionRules is only used in API level 31 and higher (current min is 19)" warning, with tools:targetApi="s" attribute as well (because older platforms simply ignore manifest-attributes they don't support, and the warning is useless).