Center toolbar elements in Xamarin formats

Question

I have a content page with a toolbar added as shown below.

Contentpage

[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class ChartList : ContentPage
{
    public ChartList ()
    {
        InitializeComponent ();

        //public class ToolbarItem : MenuItem
        ToolbarItem settings = new ToolbarItem
        {
            Icon = "icon.png",
            Text = "Settings",
            Command = new Command(this.ShowHomePage),
        };

        this.ToolbarItems.Add(settings);
    }

    private void ShowHomePage()
    {
        this.Navigation.PushAsync(new MainPage());
    }
}

App.xaml.cs

    public App()
    {
        InitializeComponent();

        ContentPage p = new MyHomeScreen2.MainPage();
        MainPage = new NavigationPage(p)
        {
            BarBackgroundColor = Color.Purple,
            BarTextColor = Color.White
        };
    }

I need to align the icon in the center of the toolbar. How to do this in Xamarin forms?