SF: Introduce VsyncTimeline to VsyncPredictor

Add the concept of timeline freezing when switching render rate.
This allow us to change render rates in sync with the app and remain
jank free across render rate changes.

Bug: 326599221
Test: Run TouchLatency, change render rate and examine Perfetto trace

Change-Id: Ibc8026434c0c1d50138299da3cb110b317604e92
diff --git a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
index 252c09c..e4ddc03 100644
--- a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
+++ b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.h
@@ -91,8 +91,8 @@
     };
 
     nsecs_t adjustVsyncIfNeeded(VSyncTracker& tracker, nsecs_t nextVsyncTime) const;
-    ArmingInfo update(VSyncTracker&, nsecs_t now, VSyncDispatch::ScheduleTiming,
-                      std::optional<ArmingInfo>) const;
+    ArmingInfo getArmedInfo(VSyncTracker&, nsecs_t now, VSyncDispatch::ScheduleTiming,
+                            std::optional<ArmingInfo>) const;
 
     const std::string mName;
     const VSyncDispatch::Callback mCallback;