I tried setting up the Galaxy Tablet to back up to Google Drive. I went to Google Drive > Settings > Backup and reset > checked 'Other device data' > Confirm.

However, on the Backup status screen, it shows:

Other device data
Couldn't turn on backup. Try again later in backup settings.

I then factory reset the device and set it up again with the same Google account, but without MDM. After that, I was able to back up to Google Drive successfully.