fix(extractors): Don't include kzip creation time in kzip (#4083)
fix(extractors): Don't include kzip creation time in kzip (#4083)

Kzips were setting the internal file modification times to when the kzip was
created. This prevents bazel from caching the results since each time the extra
action is run, it will produce a different kzip.
kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe,kythe/kythe