Change download_from_google_storage.py to not write information
for successful actions when passed the --quiet flag.

Bug: none
Change-Id: I639df538935727150e540c72681fc1d4ccc88ec5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1944168
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>