[devserver] Add sepolicy.zip artifact.

BUG=b:110011736
TEST=manual run

Change-Id: Ia53f407de7836c8ba7c32d44eacbdd1a47124bbe
Reviewed-on: https://chromium-review.googlesource.com/1114558
Commit-Ready: Qijiang Fan <fqj@google.com>
Tested-by: Qijiang Fan <fqj@google.com>
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
2 files changed