cros_config.py: Import packages from autotest_lib

Previously this code was only used by its own unit test.
But when this code gets invoked by a real test using --autotest_dir,
the imports would fail unless importing relative to autotest_lib.

TEST=python client/common_lib/cros/cros_config_unittest.py
BUG=chromium:1023647

Change-Id: Ifdd7b8b56d354b5d537a187b493c7224a910851d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1972203
Tested-by: Greg Edelston <gredelston@google.com>
Reviewed-by: Dana Goyette <dgoyette@chromium.org>
Commit-Queue: Greg Edelston <gredelston@google.com>
diff --git a/client/common_lib/cros/cros_config.py b/client/common_lib/cros/cros_config.py
index 4919c1d..5c11548 100644
--- a/client/common_lib/cros/cros_config.py
+++ b/client/common_lib/cros/cros_config.py
@@ -33,7 +33,7 @@
 import logging
 
 import common
-from client.common_lib import error
+from autotest_lib.client.common_lib import error
 
 FALLBACKS = {
         '/firmware image-name': 'mosys platform model',
diff --git a/client/common_lib/cros/cros_config_unittest.py b/client/common_lib/cros/cros_config_unittest.py
index f3ab75b..2ba3a79 100644
--- a/client/common_lib/cros/cros_config_unittest.py
+++ b/client/common_lib/cros/cros_config_unittest.py
@@ -7,9 +7,9 @@
 import unittest
 
 import common
-from client.common_lib import error
-from client.common_lib import utils
-from client.common_lib.cros import cros_config
+from autotest_lib.client.common_lib import error
+from autotest_lib.client.common_lib import utils
+from autotest_lib.client.common_lib.cros import cros_config
 
 # Lots of command-line mocking in this file.
 # Mock cros_config results are based on the path and property provided.