fix velocity

Author: Pavel Rotek

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java

@@ -314,8 +314,15 @@ public void fling(int velocityY) {
     //
     // Hence, we can use the absolute value from whatever the OS gives
     // us and use the sign of what mOnScrollDispatchHelper has tracked.
-    final int correctedVelocityY = (int)(Math.abs(velocityY) * Math.signum(mOnScrollDispatchHelper.getYFlingVelocity()));
+    //final int correctedVelocityY = (int)(Math.abs(velocityY) * Math.signum(mOnScrollDispatchHelper.getYFlingVelocity()));
 
+    //BEGIN pavel.rotek wrong velocity on old phones
+    float signum = Math.signum(mOnScrollDispatchHelper.getYFlingVelocity());
+    if (signum == 0) {
+      signum = Math.signum(velocityY);
+    }
+    final int correctedVelocityY = (int)(Math.abs(velocityY) * signum);
+    //END
 
     if (mPagingEnabled) {
       flingAndSnap(correctedVelocityY);