Packer: Multiple network interface using virutal-box iso

I am trying to use packet to create a ubuntu20.04 vm using virtualbox-iso plugin.
I am using multiple interface using “vboxmanage modifyvm <> --nic2 …” option.
I am able to see multiple multiple network interface when i started creating using packer command also.
But during the packer installation of ubuntu20.04 the installation get stuck in a window in virtualbox where its waiting for user input asking for “Your system has multiple network interface. Please select one default interface to proceed with the installation”.

When i pressed ENTER manually it proceeded with the installation. May i know how to automate this step?
Is it something i can add in “boot_command”?

Following is the boot_command im using now for ubuntu20.04.01 :

  "boot_command": [
    " auto<wait>",
    " console-setup/ask_detect=false<wait>",
    " console-setup/layoutcode=us<wait>",
    " console-setup/modelcode=pc105<wait>",
    " debconf/frontend=noninteractive<wait>",
    " debian-installer=en_US<wait>",
    " fb=false<wait>",
    " initrd=/install/initrd.gz<wait>",
    " kbd-chooser/method=us<wait>",
    " keyboard-configuration/layout=USA<wait>",
    " keyboard-configuration/variant=USA<wait>",
    " locale=en_US<wait>",
    " netcfg/get_domain=vm<wait>",
    " netcfg/get_hostname=ubuntu<wait>",
    " grub-installer/bootdev=/dev/sda<wait>",
    " noapic<wait>",
    " preseed/url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg<wait>",
    " -- <wait>",

Please clarify.