Add a command-line parameter to disable the Save command, so people
don't save and fill up my disk when I'm running this on the internet.
Change-Id: I2408e60de2d99764ac53c21c3ea784282576d400
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3808
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI