[autotest] Move 'autoupdater' module to 'server'.

The 'autoupdater' module was living under client/common_lib.
However, the module has no client-side connection; the code is
strictly server-only.  So, move the code to live under server/cros.

BUG=None
TEST=run provision in a local instance

Change-Id: I9c48d5f9ed2869cb244ab2095580314982cc1fff
Reviewed-on: https://chromium-review.googlesource.com/1058123
Commit-Ready: Richard Barnette <jrbarnette@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: David Haddock <dhaddock@chromium.org>
Reviewed-by: Congbin Guo <guocb@chromium.org>
diff --git a/server/hosts/servo_host.py b/server/hosts/servo_host.py
index e6461f6..2ce5131 100644
--- a/server/hosts/servo_host.py
+++ b/server/hosts/servo_host.py
@@ -21,19 +21,19 @@
 from autotest_lib.client.common_lib import host_states
 from autotest_lib.client.common_lib import hosts
 from autotest_lib.client.common_lib import lsbrelease_utils
-from autotest_lib.client.common_lib.cros import autoupdater
 from autotest_lib.client.common_lib.cros import dev_server
 from autotest_lib.client.common_lib.cros import retry
 from autotest_lib.client.common_lib.cros.network import ping_runner
 from autotest_lib.client.cros import constants as client_constants
 from autotest_lib.server import afe_utils
 from autotest_lib.server import site_utils as server_site_utils
+from autotest_lib.server.cros import autoupdater
 from autotest_lib.server.cros import dnsname_mangler
-from autotest_lib.server.cros.dynamic_suite import frontend_wrappers
 from autotest_lib.server.cros.dynamic_suite import control_file_getter
+from autotest_lib.server.cros.dynamic_suite import frontend_wrappers
 from autotest_lib.server.cros.servo import servo
-from autotest_lib.server.hosts import servo_repair
 from autotest_lib.server.hosts import base_classes
+from autotest_lib.server.hosts import servo_repair
 from autotest_lib.server.hosts import ssh_host
 from autotest_lib.site_utils.rpm_control_system import rpm_client