Reports sync failed notification.

Displays bar with error message and a retry button when sync fails. Closes #376 
You should use the currentAnimation pattern I have used in `BarChart` here. That will enable you to do the following:

```C#
if (currentAnimation != null) {
   // Cancel leaves the animation state mid-way complete, meaning if the bar is half hidden,
   // you can continue from there... a smoother visual experience
   currentAnimation.Cancel();
   currentAnimation = null;
}

if (conditionToShow) {
    // Note the usage of syncErrorBar.TranslationY as the start value
    var slideOut = ObjectAnimator.OfFloat(syncErrorBar, "translationY", syncErrorBar.TranslationY, 100f);
    // Other anim config
    currentAnim = slideOut;
    slideOut.Start()
} else {
    // ...
}
```