Deploying on google app engine - what do weekly restarts mean

I’m new to docker and containers and would like to deploy on google app engine. I’m happy using msqlite on the server but according to https://cloud.google.com/php/getting-started/hello-world

All flexible instances are restarted on a weekly basis. During restarts, critical, backwards-compatible updates are automatically rolled out to the underlying operating system. Your application’s image will remain the same across restarts.

Google says that my app should be stateless as well, if I used the dockerfile available on the github and used sqlite on that instance, would it be overwritten weekly?

Another option I have is to just run the cms on a VM in google compute engine, is this a better idea?