ReactSlider onValueChange

Summary:
Changelog: [Android][Fixed] - Emit the right bubbling event for ReactSliderEvent

In [ReactSliderManager.java](https://github.com/facebook/react-native/blob/main/ReactAndroid/src/main/java/com/facebook/react/views/slider/ReactSliderManager.java#L277) we register `topValueChange` yet `ReactSliderEvent` dispatches `topChange`.

Reviewed By: NickGerleman

Differential Revision: D39064685

fbshipit-source-id: c1e589c2fcaee68ef21f920a950ea36eaa0e5048

ReactAndroid/src/main/java/com/facebook/react/views/slider/ReactSliderEvent.java

@@ -15,7 +15,7 @@
 /** Event emitted by a ReactSliderManager when user changes slider position. */
 public class ReactSliderEvent extends Event<ReactSliderEvent> {
 
-  public static final String EVENT_NAME = "topChange";
+  public static final String EVENT_NAME = "topValueChange";
 
   private final double mValue;
   private final boolean mFromUser;