import: `--no-download` doesn't save rev_lock

[dberenbaum]

Good catch! You're right, there's no hash values in deps for import --no-download, which means that the dependencies aren't actually locked. Will need to fix this in dvc too. c.c. @dberenbaum

Originally posted by @dtrifiro in https://github.com/iterative/dvc.org/pull/3930#discussion_r971851854