[SF] Adds Refresh Rate Indicator HWC callback handlers

Adds onRefreshRateChangedDebug handling
Implementation details will follow in the upcoming CLS.
Test: Device boots
BUG: 202734676

Change-Id: I7e4c1f43712661627de02199ba900d520fa24dc3
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 169e101..37175ac 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2085,6 +2085,10 @@
     mScheduler->forceNextResync();
 }
 
+void SurfaceFlinger::onRefreshRateChangedDebug(const RefreshRateChangedDebugData&) {
+    // TODO(b/202734676) update refresh rate value on the RefreshRateOverlay
+}
+
 void SurfaceFlinger::setVsyncEnabled(bool enabled) {
     ATRACE_CALL();