SF: Adding sysprop flag for video detection

The flag will be turned on in a new CL.

Test: manual
Bug: 126272046

Change-Id: Ie15c0abbde641a731616cf94b076e43feafe7bc7
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index 949c23c..fe6dc93 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -297,3 +297,13 @@
     access: Readonly
     prop_name: "ro.surface_flinger.set_idle_timer_ms"
 }
+
+# useSmart90ForVideo indicates whether Scheduler should detect content FPS, and try to adjust the
+# screen refresh rate based on that.
+prop {
+    api_name: "use_smart_90_for_video"
+    type: Boolean
+    scope: Internal
+    access: Readonly
+    prop_name: "ro.surface_flinger.use_smart_90_for_video"
+}