address review comments

Author: sadhansood

crates/walrus-sdk/client_config_example.yaml

@@ -46,6 +46,7 @@ communication_config:
     min_blob_size_bytes: 52428800
   upload_mode: balanced
   pending_uploads_enabled: false
+  optimistic_upload_max_blob_bytes: 4194304
   registration_delay_millis: 200
   max_total_blob_size: 1073741824
   committee_change_backoff: