docs: tightened requirements on cloud storage subscription filename s…

…uffixes (#938)

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 543503563

Source-Link: https://togithub.com/googleapis/googleapis/commit/212ecef96e3ea7c67465ff3f52680301ad0ea1f9

Source-Link: https://togithub.com/googleapis/googleapis-gen/commit/532d27eea6ff128fdcbb3332176e894e76dcc685
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNTMyZDI3ZWVhNmZmMTI4ZmRjYmIzMzMyMTc2ZTg5NGU3NmRjYzY4NSJ9

google/pubsub_v1/types/pubsub.py

@@ -1212,6 +1212,7 @@ class CloudStorageConfig(proto.Message):
             User-provided suffix for Cloud Storage filename. See the
             `object naming
             requirements <https://cloud.google.com/storage/docs/objects#naming>`__.
+            Must not end in "/".
         text_config (google.pubsub_v1.types.CloudStorageConfig.TextConfig):
             If set, message data will be written to Cloud
             Storage in text format.