Enable SeedVault RoundSync support
## Summary
Seedvault supports RoundSync since commit [db1fc90](https://github.com/seedvault-app/seedvault/commit/db1fc905899e920674a72a02d354accc54470ff2) and version [14-4.1](https://github.com/seedvault-app/seedvault/releases/tag/14-4.1). The SeedVault changelog says: "Support for RoundSync (if enabled by the OS)". However, this feature is not enabled in /e/os. It would be useful to sync the backup to [Google Drive](https://rclone.org/drive/) ([#167](https://github.com/seedvault-app/seedvault/issues/167)), [Seafile](https://rclone.org/seafile/) ([#169](https://github.com/seedvault-app/seedvault/issues/169)), [pCloud](https://rclone.org/pcloud/) ([#229](https://github.com/seedvault-app/seedvault/issues/229)), [SFTP](https://rclone.org/sftp/) ([#173](https://github.com/seedvault-app/seedvault/issues/173)), [WebDav](https://rclone.org/webdav/) (#317) and #196, [Proton Drive](https://rclone.org/protondrive/) (#520) and [Mega](https://rclone.org/mega/) ([#311](https://github.com/seedvault-app/seedvault/issues/311)).
## Description
Examples:
REQ1: As a user of SeedVault, I want to sync my backup to ProtonDrive, in order to automatically save my backup file.
task