Fix AU test getting incorrect devserver URL

AU test should use keyword arguments (e.g. port, sub_dir) when
calling dev_server_wrapper.DevServerWrapper methods.

BUG=chromium:321684
CQ-DEPEND=CL:181361
TEST=x86-mario-paladin (vmtest) trybot

Change-Id: Ied965a8f8788f6c625d19e28f677dfcadfee6521
Reviewed-on: https://chromium-review.googlesource.com/182240
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
Tested-by: Yu-Ju Hong <yjhong@chromium.org>
Commit-Queue: Yu-Ju Hong <yjhong@chromium.org>
2 files changed