A break the Google Play Services app, version 26.32.31 Beta It reveals some interesting details on the backup of the phone. It suggests a new functionality that Google will probably implement in the near future that would allow you to choose multiple folders to backup.

Anyone who uses automatic online backup knows that not all data is backup. Get your photos and videos in the cloud together with settings and some user data, but not everything. For example, some apps have encrypted data and they cannot be backup.
Currently you cannot back up other folders, such as the “Download” folder. But the source code of the beta version for Google Play Services suggests that Google is working on a solution. It will probably give you the opportunity to backup the download folder and because not other folders. Of course, all your data will be uploaded to your Google drive.
In addition, there is a string that refers to “documents”, which may suggest that Google will allow backup of only some types of files and not everything.
In any case, we can only guess for now, but it seems that Google is already working on the new backup options in order to know with certainty soon soon.

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