Also enable post-upload-hooks

R=machenbach@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I8001394454f5d71d48a5e6261c891d6c7c2c3825
Reviewed-on: https://chromium-review.googlesource.com/518167Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45590}