fix: using location and project parsed from resource name if not provided

Author: racinmat

google/cloud/aiplatform/models.py

@@ -5240,8 +5240,8 @@ def __init__(
         # Create ModelRegistry with the unversioned resource name
         self._registry = ModelRegistry(
             self.resource_name,
-            location=location,
-            project=project,
+            location=location or self.location,
+            project=project or self.project,
             credentials=credentials,
         )