如何在itext android中增加列表项目符号大小？

import com.itextpdf.text.Chunk;
import com.itextpdf.text.Document;
import com.itextpdf.text.Element;
import com.itextpdf.text.List;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.pdf.draw.DrawInterface;

public class CustomListSymbol implements DrawInterface {
    private float fontSize;

    public CustomListSymbol(float fontSize) {
        this.fontSize = fontSize;
    }

    @Override
    public void draw(PdfContentByte canvas, float llx, float lly, float urx, float ury, float y) {
        canvas.saveState();
        canvas.beginText();
        canvas.setFontAndSize(canvas.getFont().getBaseFont(), fontSize);
        canvas.showTextAligned(Element.ALIGN_LEFT, "•", llx, y, 0);
        canvas.endText();
        canvas.restoreState();
    }
}

public class ListExample {
    public static void main(String[] args) {
        Document document = new Document();
        try {
            PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("list_example.pdf"));
            document.open();

            List list = new List();
            list.setListSymbol(new CustomListSymbol(12)); // 设置列表项符号的大小为12

            list.add(new Chunk("Item 1"));
            list.add(new Chunk("Item 2"));
            list.add(new Chunk("Item 3"));

            document.add(list);
            document.close();
            writer.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}