message: Fired js events only when tab changed
  This matches the old segmented code which matches android
diff: - (void)setCurrentTab:(NSInteger)index
  {
  _nativeEventCount++;
  - [self.tabChange tabSelected:index];
  + if (index != _selectedTab) {
  self.onTabSelected(@{
  @"tab": @(index),
  @"eventCount": @(_nativeEventCount),
  if (!!tabBarItem.onPress) {
  tabBarItem.onPress(nil);
  }
  + }
  + [self.tabChange tabSelected:index];
  [_pageViewController setViewControllers:@[_tabs[index]] direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
  _selectedTab = index;
  _selectedTabView = _tabs[index];
  