Make container entrypoint script more flexible
Previously, the container entrypoint (which is hard to override)
invariably called the Python script. Now the entrypoint script will run
anything passed as arguments to it, and the container will default to
running the monitor-gating script. This is to let users e.g. run a shell
to inspect things more easily.
Signed-off-by: Nils Philippsen <nils@redhat.com>