Expand group when clicking on grouped read receipt.

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemGroupedEventsRow.kt

@@ -148,7 +148,8 @@ private fun TimelineItemGroupedEventsRowContent(
                     receipts = timelineItem.aggregatedReadReceipts,
                 ),
                 showReadReceipts = true,
-                onReadReceiptsClicked = { /* No op for group event */ })
+                onReadReceiptsClicked = onExpandGroupClick
+            )
         }
     }
 }