SF: use SurfaceFlingerProperties for frame_rate_override_global

This flag is accessed from DisplayManager in addition to SF,
so add it to SurfaceFlingerProperties instead of hardcoded flag.

Test: atest DisplayModeDirectorTests
Bug: 241447632
Change-Id: I1951bc5e17ec0f6304ecb91aa83555b8cce5e73a
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index 28da81f..8540c3d 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -447,8 +447,8 @@
 
 # Limits the frame rate override feature (enable_frame_rate_override) to override the refresh rate
 # to native display refresh rates only. Before introducing this flag, native display refresh rates
-# was the default behvaiour. With this flag we can control which behaviour we want explicitly.
-# This flag is intoruduced as a fail-safe machanism and planned to be defaulted to false.
+# was the default behaviour. With this flag we can control which behaviour we want explicitly.
+# This flag is introduced as a fail-safe mechanism and planned to be defaulted to false.
 prop {
     api_name: "frame_rate_override_for_native_rates"
     type: Boolean
@@ -457,6 +457,16 @@
     prop_name: "ro.surface_flinger.frame_rate_override_for_native_rates"
 }
 
+# Enables the frame rate override feature (enable_frame_rate_override) to
+# override the frame rate globally instead of only for individual apps.
+prop {
+    api_name: "frame_rate_override_global"
+    type: Boolean
+    scope: Public
+    access: Readonly
+    prop_name: "ro.surface_flinger.frame_rate_override_global"
+}
+
 # Enables Layer Caching
 prop {
     api_name: "enable_layer_caching"