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/SurfaceFlingerProperties.h b/services/surfaceflinger/SurfaceFlingerProperties.h
index 5e316cf..09629cf 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.h
+++ b/services/surfaceflinger/SurfaceFlingerProperties.h
@@ -98,6 +98,8 @@
 
 bool frame_rate_override_for_native_rates(bool defaultValue);
 
+bool frame_rate_override_global(bool defaultValue);
+
 bool enable_layer_caching(bool defaultValue);
 
 bool enable_sdr_dimming(bool defaultValue);