Refactor acloud.public.errors to acloud.errors.

Bug: 113753798
Test: atest acloud_test && run acloud create/list/delete
Change-Id: I03b4b34769d754bfebd279895b0ca44311bbecc7
diff --git a/internal/lib/gcompute_client_test.py b/internal/lib/gcompute_client_test.py
index b84cdbd..a34bfa2 100644
--- a/internal/lib/gcompute_client_test.py
+++ b/internal/lib/gcompute_client_test.py
@@ -25,10 +25,10 @@
 # pylint: disable=import-error
 import apiclient.http
 
+from acloud import errors
 from acloud.internal.lib import driver_test_lib
 from acloud.internal.lib import gcompute_client
 from acloud.internal.lib import utils
-from acloud.public import errors
 
 GS_IMAGE_SOURCE_URI = "https://storage.googleapis.com/fake-bucket/fake.tar.gz"
 GS_IMAGE_SOURCE_DISK = (