SurfaceFlingerProperties: Use proper prop scope

* System scope is deperecated,
  Public scope should be used instead

Test: m
Change-Id: I9fc658487397f1dfb2175d071736e0bc1eb3ad04
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index ef43440..8ed454f 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -308,7 +308,7 @@
 prop {
     api_name: "refresh_rate_switching"
     type: Boolean
-    scope: System
+    scope: Public
     access: Readonly
     prop_name: "ro.surface_flinger.refresh_rate_switching"
 }