Should full backup content xml file be empty or not added at all to include all?

Question

So I was adding some stuff to my application manifest and I saw that I had a warning on my application tag:

On SDK version 23 and up, your app data will be automatically backed up and restored on app install. Consider adding the attribute android:fullBackupContent to specify an @xml resource which configures which files to backup.

And then I searched up for that. Apparently there are only 2 tags for that: <include> and <exclude>. I don't want to exclude any files from the backup as I don't have any local-depending files, and I don't need any <include> tags as

<include>: Specifies a set of resources to back up, instead of having the system back up all data in your app by default.

When I saw that if I don't put any <include> tags, then the system will back up all data in your app by default, which is exactly what I want.

Now I have this question: should I add the backup_content.xml file, but empty as the default settings are good, or not add the file at all? (in which case Android Studio will complain)

Answer 1

Fast Solution:

AndroidManifest.xml

<application     android:allowBackup="true"     android:fullBackupContent="true"     ...     ...     ... </application> 

For more details see: https://developer.android.com/guide/topics/data/autobackup

Answer 2

If you want to silence the warnings, but don't need to exclude any files from the backup, you could also just add tools:ignore="AllowBackup" to the application tag in your AndroidManifest.xml to suppress the warning (or use the Suppress button that you get when viewing the warning details).