如何使我的AlertDialog标题居中？

<style name="CustomAlertDialog" parent="Theme.AppCompat.Light.Dialog.Alert">
    <item name="android:windowTitleStyle">@style/CustomDialogTitle</item>
</style>

<style name="CustomDialogTitle">
    <item name="android:textAlignment">center</item>
</style>

AlertDialog.Builder builder = new AlertDialog.Builder(context, R.style.CustomAlertDialog);
builder.setTitle("对话框标题");
builder.setMessage("对话框内容");
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        // 点击确定按钮的逻辑处理
    }
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        // 点击取消按钮的逻辑处理
    }
});
AlertDialog dialog = builder.create();
dialog.show();