firewalld: Run 'iptables' as a regular user.

BUG=chromium:487019
TEST=Unit tests, platform_Firewall
CQ-DEPEND=CL:270621

Change-Id: Ic49e7d7912d96f9cec29cf2a3f34f50e71c02391
Reviewed-on: https://chromium-review.googlesource.com/270170
Trybot-Ready: Jorge Lucangeli Obes <jorgelo@chromium.org>
Tested-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Bartosz Fabianowski <bartfab@chromium.org>
Commit-Queue: Jorge Lucangeli Obes <jorgelo@chromium.org>
2 files changed