fix: Ignore unknown fields in rest streaming. (#651)

* Ignore unknown fields in rest streaming.

If the api adds a new field to a stremaing response, it shouldn't break old clients.

We found this in the google.ai.generativelanguage API. Colab forces our clients to use rest, so all our streaming examples broke when the API team rolled out a new field.

* format

---------

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: MarkDaoust

google/api_core/rest_streaming.py

@@ -118,7 +118,9 @@ def __next__(self):
     def _grab(self):
         # Add extra quotes to make json.loads happy.
         if issubclass(self._response_message_cls, proto.Message):
-            return self._response_message_cls.from_json(self._ready_objs.popleft())
+            return self._response_message_cls.from_json(
+                self._ready_objs.popleft(), ignore_unknown_fields=True
+            )
         elif issubclass(self._response_message_cls, google.protobuf.message.Message):
             return Parse(self._ready_objs.popleft(), self._response_message_cls())
         else: