SF: avoid a composition cycle when the FrameRate votes updates

SF would still do a composition if the display mode changes, but
it is not required for every frame rate vote change.

Bug: 339759346
Test: android.platform.test.scenario.gmail.OpenCloseComposeEmailMicrobenchmark#testOpenCloseComposeEmail
Change-Id: Ia01a13b1a167b3a0a67cf7be3db5e64b9405580a
diff --git a/services/surfaceflinger/FrontEnd/RequestedLayerState.h b/services/surfaceflinger/FrontEnd/RequestedLayerState.h
index 09f33de..4829d4c 100644
--- a/services/surfaceflinger/FrontEnd/RequestedLayerState.h
+++ b/services/surfaceflinger/FrontEnd/RequestedLayerState.h
@@ -57,6 +57,7 @@
         BufferSize = 1u << 18,
         GameMode = 1u << 19,
         BufferUsageFlags = 1u << 20,
+        RequiresComposition = 1u << 21,
     };
     static Rect reduce(const Rect& win, const Region& exclude);
     RequestedLayerState(const LayerCreationArgs&);