[AC-4782] Ti.Blob imageAsCompressed function does not exist

compressImage: function(original) {
    var image = this.resizeImage(original);
    return image.imageAsCompressed(.75);
  },
  resizeImage: function(original) {
    if (original.width < maxWidth && original.height < maxHeight) {
      return original;
    }
    
    var aspectRatio = original.width / original.height;
    if (original.width <= original.height) {      
      return original.imageAsResized(aspectRatio * maxHeight, maxHeight);  
    }
    
    return original.imageAsResized(maxWidth, maxWidth / aspectRatio);
  },