Update attributes set in trailer (#366)

Author: lukasIO

livekit-rtc/livekit/rtc/data_stream.py

@@ -70,6 +70,8 @@ async def _on_chunk_update(self, chunk: proto_DataStream.Chunk):
         await self._queue.put(chunk)
 
     async def _on_stream_close(self, trailer: proto_DataStream.Trailer):
+        self.info.attributes = self.info.attributes or {}
+        self.info.attributes.update(trailer.attributes)
         await self._queue.put(None)
 
     def __aiter__(self) -> AsyncIterator[str]:
@@ -118,6 +120,8 @@ async def _on_chunk_update(self, chunk: proto_DataStream.Chunk):
         await self._queue.put(chunk)
 
     async def _on_stream_close(self, trailer: proto_DataStream.Trailer):
+        self.info.attributes = self.info.attributes or {}
+        self.info.attributes.update(trailer.attributes)
         await self._queue.put(None)
 
     def __aiter__(self) -> AsyncIterator[bytes]: