message: Removed unused event parameters
  Will navigate only needs crumb and did navigate only needs eventCount
diff: _navigationController.delegate = nil;
  }
  -- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
  +- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
  {
  NSInteger crumb = [navigationController.viewControllers indexOfObject:viewController];
  if (crumb < [self.keys count] - 1) {
  _nativeEventCount++;
  - self.onDidNavigateBack(@{
  + self.onWillNavigateBack(@{
  @"crumb": @(crumb),
  - @"eventCount": @(_nativeEventCount),
  });
  }
  }
  -- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
  +- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
  {
  NSInteger crumb = [navigationController.viewControllers indexOfObject:viewController];
  if (crumb < [self.keys count] - 1) {
  _nativeEventCount++;
  - self.onWillNavigateBack(@{
  - @"crumb": @(crumb),
  + self.onDidNavigateBack(@{
  @"eventCount": @(_nativeEventCount),
  });
  }
  