Include bundled aggregations in /sync and related fixes (#11478)

Due to updates to MSC2675 this includes a few fixes:

* Include bundled aggregations for /sync.
* Do not include bundled aggregations for /initialSync and /events.
* Do not bundle aggregations for state events.
* Clarifies comments and variable names.

1 files changed, 4 insertions, 5 deletions

diff --git a/synapse/rest/client/relations.py b/synapse/rest/client/relations.py

index b1a3304849..fc4e6921c5 100644
--- a/synapse/rest/client/relations.py
+++ b/synapse/rest/client/relations.py
@@ -224,14 +224,13 @@ class RelationPaginationServlet(RestServlet):
         )
 
         now = self.clock.time_msec()
-        # We set bundle_relations to False when retrieving the original
-        # event because we want the content before relations were applied to
-        # it.
+        # Do not bundle aggregations when retrieving the original event because
+        # we want the content before relations are applied to it.
         original_event = await self._event_serializer.serialize_event(
-            event, now, bundle_relations=False
+            event, now, bundle_aggregations=False
         )
         # The relations returned for the requested event do include their
-        # bundled relations.
+        # bundled aggregations.
         serialized_events = await self._event_serializer.serialize_events(events, now)
 
         return_value = pagination_chunk.to_dict()