Skip gclient auto-update for "getdep", "root", "help", "--help"
These are all things I would expect to not hit the network.
Bug: None
Change-Id: I44bddd94e8da13df57f3cd068def9a5e51774bc0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4161184
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>