autoupdate_EndToEndTest: partial revert of commit 0c88356d.

We want tests to be narrow in scope and autoupdate only to check updates.
There is no point in starting ARC container. All that adds at this stage
is flakes in update test. ARC is checked by other tests later.

BUG=chromium:709710
TEST=None.

Change-Id: Ie928fadb49241d5f0cc8276262c388ffb394682b
Reviewed-on: https://chromium-review.googlesource.com/407581
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Tested-by: Ilja H. Friedel <ihf@chromium.org>
diff --git a/server/site_tests/autoupdate_EndToEndTest/autoupdate_EndToEndTest.py b/server/site_tests/autoupdate_EndToEndTest/autoupdate_EndToEndTest.py
index 17c1fb6..5a07c21 100755
--- a/server/site_tests/autoupdate_EndToEndTest/autoupdate_EndToEndTest.py
+++ b/server/site_tests/autoupdate_EndToEndTest/autoupdate_EndToEndTest.py
@@ -1093,7 +1093,7 @@
         else:
             logging.info('Attempting to login (release %s).', release_string)
             client_at = autotest.Autotest(self._host)
-            client_at.run_test('login_LoginSuccess', arc_mode='enabled')
+            client_at.run_test('login_LoginSuccess')
 
 
     def _start_perf_mon(self, bindir):