Not having the --rm flag causes docker containers to be stored forever,
so make sure we always add it to the "docker run" commands that we run
on jenkins via scripts in various repositories.
Depends: docker-playground I48b01c43fedf379b8a565eaab0369806d7831bd8
Related: https://osmocom.org/projects/osmocom-servers/wiki/Docker_cache_clean_up
Related: SYS#5827, OS#5099
Change-Id: I8ab9c291504475d670bdefc50c4524c5bdd4c880
