Avoid overwriting '__module__' of messages from shared modules. (#5364)

Note that we *are* still overwriting it for messages from modules defined
within the current package.

See #4715.

packages/google-cloud-bigquery-datatransfer/google/cloud/bigquery_datatransfer_v1/types.py

@@ -15,11 +15,7 @@
 from __future__ import absolute_import
 import sys
 
-from google.api_core.protobuf_helpers import get_messages
-
 from google.api import http_pb2
-from google.cloud.bigquery_datatransfer_v1.proto import datatransfer_pb2
-from google.cloud.bigquery_datatransfer_v1.proto import transfer_pb2
 from google.protobuf import any_pb2
 from google.protobuf import descriptor_pb2
 from google.protobuf import duration_pb2
@@ -30,21 +26,38 @@
 from google.protobuf import wrappers_pb2
 from google.rpc import status_pb2
 
+from google.api_core.protobuf_helpers import get_messages
+from google.cloud.bigquery_datatransfer_v1.proto import datatransfer_pb2
+from google.cloud.bigquery_datatransfer_v1.proto import transfer_pb2
+
+
+_shared_modules = [
+    http_pb2,
+    any_pb2,
+    descriptor_pb2,
+    duration_pb2,
+    empty_pb2,
+    field_mask_pb2,
+    struct_pb2,
+    timestamp_pb2,
+    wrappers_pb2,
+    status_pb2,
+]
+
+
+_local_modules = [
+    datatransfer_pb2,
+    transfer_pb2,
+]
+
 names = []
-for module in (
-        http_pb2,
-        datatransfer_pb2,
-        transfer_pb2,
-        any_pb2,
-        descriptor_pb2,
-        duration_pb2,
-        empty_pb2,
-        field_mask_pb2,
-        struct_pb2,
-        timestamp_pb2,
-        wrappers_pb2,
-        status_pb2,
-):
+
+for module in _shared_modules:
+    for name, message in get_messages(module).items():
+        setattr(sys.modules[__name__], name, message)
+        names.append(name)
+
+for module in _local_modules:
     for name, message in get_messages(module).items():
         message.__module__ = 'google.cloud.bigquery_datatransfer_v1.types'
         setattr(sys.modules[__name__], name, message)