Throttling logic in `onScroll` seems to be backwards/incorrect (i.e. it always updates)

[zzorba]

While investigating some slow updates (repeatedly seeing old content as I scrolled -- more visible on Android but also happening pretty regularly on iOS) I noticed this line of code which appears to be doing nothing?

react-native-largelist/src/LargeList.js

Lines 453 to 458 in d93c898

	const now = new Date().getTime();
	if (this._lastTick - now > 30) {
	this._lastTick = now;
	return;
	}
	this._lastTick = now;

this._lastTick will always be less than now, so the early return will never be executed AFAICT. Diagnosing it with some console.logs showed this to be the case as well (the early return never executed).

I think this logic should be inverted as follows:

    const now = new Date().getTime();
    if (now - this._lastTick < 30) {
      return;
    }
    this._lastTick = now;
    this._shouldUpdateContent &&
      this._groupRefs.forEach((group) =>
        idx(() => group.current.contentConversion(offsetY))
      );

And possibly it should be using the updateTimeInterval prop which currently seems to be documented, but completely unused in the code (unless I missed something).