How do I Set the Icon for the MasterDetailPage Master Icon using a drawable?

How do I SetIcon for the MasterDetailPage Master Icon? The following code will only update the actionBar Icon Drawable.

The MasterDetailPage.Master.Icon attribute only accepts a FileImageSource and I'm creating a drawable from a Font (*.tff file).

 public class MyMasterDetailRenderer : MasterDetailRenderer
    {
        protected override void OnAttachedToWindow()
        {
            base.OnAttachedToWindow();            
            var actionBar = ((Activity)this.Context)?.ActionBar;
            if (actionBar != null)
            {

                var fontDrawable = new FontDrawable(this.Context, StyleKit.SpinIcon, Color.White.ToAndroid(), 32);               
                actionBar.SetIcon(fontDrawable);
            }
        }
    }