You can mount your Google Drive onto the Chromebook's file system. Then, you can share your file system's Google Drive folder with Crostini. Seems easy, which it should be and is. But it's just part of the genius of Chromebooks. In a true Linux distro, on the other hand, I found that it's just about as easy as it is on a Chromebook only if you use one type of desktop environment. It builds in similar automation. But if you use a distro that's based on the very popular KDE Plasma desktop environment, you're in for a very rough ride indeed. (But rclone does accomplish the same thing if you're willing to suffer through the command line installation and setup and then a create a shell script file that runs at OS startup.)