If you’re just worried about backup/restore, and not upgrade, then you can start your container with a volume, and then refer to that volume later when starting another container.
This creates a data-only mattermost container, adding a Volume to the container, while removing the other container args:
docker run --name mattermost-data -v /mattermost-data mattermost/platform:latest
Now, when you run a mattermost container, you should instead run it like so:
docker run --name mattermost-dev -d --publish 8065:80 --volumes-from mattermost-data mattermost/platform:latest
Each time you run a new container using the --volumes-from=mattermost-data, you will use, and save to that data only container.