[crostestutils] Suppress verbose run_remote_tests.sh output during AU tests

Now that we pull more detailed test failure info into the test summary
generated at the end of run_remote_tests.sh, we don't need the verbose output.
Pass --verbose=0 to cros_run_vm_test to suppress this noise.

BUG=chromium-os:40426
TEST=ctest.py  --quick -b x86-generic

Change-Id: Ideadfe55e272ec46970e8873cd4d3875e865f59f
Reviewed-on: https://gerrit.chromium.org/gerrit/10905
Commit-Ready: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
diff --git a/au_test_harness/vm_au_worker.py b/au_test_harness/vm_au_worker.py
index 6a4b588..adb199a 100644
--- a/au_test_harness/vm_au_worker.py
+++ b/au_test_harness/vm_au_worker.py
@@ -99,6 +99,7 @@
                '--kvm_pid=%s' % self._kvm_pid_file,
                '--ssh_port=%s' % self._ssh_port,
                '--results_dir_root=%s' % log_directory_in_chroot,
+               '--verbose=0',
                test,
               ]
     if self.graphics_flag: command.append(self.graphics_flag)