Refactor acloud.public.errors to acloud.errors.

Bug: 113753798
Test: atest acloud_test && run acloud create/list/delete
Change-Id: I03b4b34769d754bfebd279895b0ca44311bbecc7
diff --git a/public/config_test.py b/public/config_test.py
index dd4e757..e6cf679 100644
--- a/public/config_test.py
+++ b/public/config_test.py
@@ -21,10 +21,10 @@
 import mock
 
 # pylint: disable=no-name-in-module,import-error
+from acloud import errors
 from acloud.internal.proto import internal_config_pb2
 from acloud.internal.proto import user_config_pb2
 from acloud.public import config
-from acloud.public import errors
 
 
 class AcloudConfigManagerTest(unittest.TestCase):