VelocityTracker Cleanups: Differential Axes Support Follow Up

This CL follows ag/19950271. It:
- fixes a param name, to make it consistent with the latest terminology we use (and the one we use in the .cpp file)
- add comment to the VelocityTrackr#createStrategy function about this param

Bug: 32830165
Change-Id: Idf90547c6b9629e98ee9014549085a1db9024700
Test: tests unaffected (trivial naming/comment change)
diff --git a/include/input/VelocityTracker.h b/include/input/VelocityTracker.h
index f6556d6..294879e 100644
--- a/include/input/VelocityTracker.h
+++ b/include/input/VelocityTracker.h
@@ -160,8 +160,12 @@
 
     void configureStrategy(int32_t axis);
 
+    // Generates a VelocityTrackerStrategy instance for the given Strategy type.
+    // The `deltaValues` parameter indicates whether or not the created strategy should treat motion
+    // values as deltas (and not as absolute values). This the parameter is applicable only for
+    // strategies that support differential axes.
     static std::unique_ptr<VelocityTrackerStrategy> createStrategy(const Strategy strategy,
-                                                                   bool isCumulative);
+                                                                   bool deltaValues);
 };