Convert get_rooms to use runInteraction so the transacion has a more helpful description

synapse/storage/room.py

@@ -82,6 +82,7 @@ class RoomStore(SQLBaseStore):
             "topic" key if one is set, and a "name" key if one is set
         """
 
+        def f(txn):
             topic_subquery = (
                 "SELECT topics.event_id as event_id, "
                 "topics.room_id as room_id, topic "
@@ -113,7 +114,13 @@ class RoomStore(SQLBaseStore):
                 "name": name_subquery,
             }
 
-        rows = yield self._execute(None, sql, is_public)
+            c = txn.execute(sql, (is_public,))
+
+            return c.fetchall()
+
+        rows = yield self.runInteraction(
+            "get_rooms", f
+        )
 
         ret = [
             {