I managed to partially fix that by changing Umbraco code itself. I changed line
<ul class="file-list" ng-show="done.length > 0 || queue.length > 0 || rejected.length > 0"> umb-file-dropzone.html to
<ul class="file-list" ng-show="done.length > 0 || queue.length >= 0 || rejected.length > 0"> and now I have a progress bar. But once uploaded, There is no success message, instead dashboard reloads and new file shows in list of files. I tried to add custom messages on saved event like this

 private void MediaService_Saved(IMediaService sender, SaveEventArgs<IMedia> e)
 {
     foreach (var mediaitem in e.SavedEntities)
     {
        EventMessage message = new EventMessage("Saved", "Succesfully Uploaded", EventMessageType.Success);
        e.Messages.Add(message); 
     }
 }

But message type shows as error, I tried others(Warning, Info, Default) they all look like Error message. And if I add message, file doesn't show as uploaded on dashboard list of files and for like 70 seconds it's impossible to click anything on the page. It's just stuck.

Any advice how to get client some feedback that uploading was success?