Set Will-Show-Survey Handler

This handler can be used to run a block of code right before a survey is shown to the user.

Surveys.willShowSurveyHandler = {
    // Change some state
}

IBGSurveys.willShowSurveyHandler = ^{
    // Change some state
};

Surveys.setOnShowCallback(new Runnable() {
    @Override
    public void run() {
        //Pause game
    }
});

Surveys.setOnShowCallback(OnShowCallback {
                //Pause game
            }            
        )

Surveys.setOnShowHandler(() => {
  //Perform any changes before the survey appears.
});

Surveys.setOnShowCallback(Function function);

Surveys.setOnShowHandler(
  function () {
        console.log('On show survey');
  },
  function (error) {
        console.log('On show handler could not be set ' + error);
  }
);

//iOS
IBGSurveys.WillShowSurveyHandler = () =>
{
  System.Console.WriteLine("New Survey");
};

//Android
Surveys.SetOnShowCallback(new IPreShowingSurveyRunnable());
public class IPreShowingSurveyRunnable : Java.Lang.Object, IOnShowCallback
{
  public void OnShow()
  {
    Android.Util.Log.Warn("PreShowingSurvey", "Pre Showing survey");
  }
}