fix(generator): update fallback proto-plus check to exactly match api_core requests.py

Author: hebaalazzeh

packages/gapic-generator/gapic/templates/%namespace/%name_%version/%sub/_compat.py.j2

@@ -30,7 +30,7 @@ except ImportError:  # pragma: NO COVER
                     setattr(request, field_name, request_id_val)
             except (AttributeError, ValueError):
                 # Proto-plus messages or other objects
-                if not getattr(request, field_name, None):
+                if getattr(request, field_name, None) is None:
                     setattr(request, field_name, request_id_val)
         else:
             if not getattr(request, field_name, None):

packages/gapic-generator/tests/integration/goldens/storagebatchoperations/google/cloud/storagebatchoperations_v1/_compat.py

@@ -43,8 +43,8 @@ def setup_request_id(request, field_name: str, is_proto3_optional: bool):  # pra
                     setattr(request, field_name, request_id_val)
             except (AttributeError, ValueError):
                 # Proto-plus messages or other objects
-                if not getattr(request, field_name, None):
+                if getattr(request, field_name, None) is None:
                     setattr(request, field_name, request_id_val)
         else:
-            if not getattr(request, field_name, None):
+            if getattr(request, field_name, None) is None:
                 setattr(request, field_name, request_id_val)