message: Incremented count only after did navigate
  The will navigate doesn't do anything so no need to increment there
diff: {
  NSInteger crumb = [navigationController.viewControllers indexOfObject:viewController];
  if (crumb < [self.keys count] - 1) {
  - _nativeEventCount++;
  self.onWillNavigateBack(@{
  @"crumb": @(crumb),
  });
  