SF: Add mirror layers to transaction trace

Test: atest TransactionTracingTest
Bug: 200284593
Change-Id: I40fbf806f68c6b0bad29fb4568ac5ae1a547cc3b
diff --git a/services/surfaceflinger/layerproto/transactions.proto b/services/surfaceflinger/layerproto/transactions.proto
index 10222cc..e31b502 100644
--- a/services/surfaceflinger/layerproto/transactions.proto
+++ b/services/surfaceflinger/layerproto/transactions.proto
@@ -53,6 +53,7 @@
     string name = 2;
     uint32 flags = 3;
     int32 parent_id = 4;
+    int32 mirror_from_id = 5;
 }
 
 message TransactionState {