Description of problem:
Guests won't have network after v2v conversion if source vmware guest's network is attached to standard switch but no entry 'ethernet0.networkName'

Version-Release number of selected component (if applicable):
virt-v2v-2.0.7-6.el9.x86_64
libguestfs-1.48.4-2.el9.x86_64
libvirt-libs-8.7.0-1.el9.x86_64
qemu-img-7.1.0-1.el9.x86_64
nbdkit-server-1.30.8-1.el9.x86_64
libnbd-1.12.6-1.el9.x86_64
guestfs-tools-1.48.2-5.el9.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Prepare a VMware guest and assign a network which is connected to a standard switch of ESXi host to the guest, but the guest vmx file doesn't have entry
'ethernet0.networkName'

#cat esx7.0-rhel9.1-x86_64-uefi-without-secureboot.vmx |grep ethernet
ethernet0.virtualDev = "vmxnet3"
ethernet0.addressType = "vpx"
ethernet0.generatedAddress = "00:50:56:96:4d:83"
ethernet0.uptCompatibility = "TRUE"
ethernet0.present = "TRUE"
ethernet0.pciSlotNumber = "192"
ethernet0.exposeLargeBAR = "TRUE"

2. Use virsh to dump the guest xml from VMware

1. virsh -c vpx://root@10.73.213.107/data/10.73.212.38/?no_verify=1 dumpxml Auto-esx7.0-rhel9.1-x86_64-uefi-without-network-name
   Enter root's password for 10.73.213.107:
   <domain type='vmware' xmlns:vmware='http://libvirt.org/schemas/domain/vmware/1.0'>
   <name>Auto-esx7.0-rhel9.1-x86_64-uefi-without-network-name</name>
   ....
   <interface type='null'>
   <mac address='00:50:56:96:4d:83' type='generated'/>
   <model type='vmxnet3'/>
   </interface>
   .....

3. Convert the guest from VMware to rhv by v2v
virt-v2v -ic vpx://root@10.73.213.107/data/10.73.212.38/?no_verify=1 -it vddk -io vddk-libdir=/home/vddk7.0.3 -io vddk-thumbprint=87:F9:29:E7:33:DE:34:68:74:3F:6A:C9:61:96:C3:51:E2:1E:EA:2B -o rhv-upload -oc https://dell-per740-22.lab.eng.pek2.redhat.com/ovirt-engine/api -op /home/rhvpasswd -os nfs_data -ip /home/passwd Auto-esx7.0-rhel9.1-x86_64-uefi-without-network-name --mac 00:50:56:96:4d:83:bridge:ovirtmgmt -v -x |& tee > v2v-convert-guest-with-standard-switch-no-entry-network-name.log
█ 100% [****************************************]

4. Check the guest after conversion, found guest has no network, pls refer to attached screenshot

Actual results:
As above description

Expected results:
Guests have network after v2v conversion or v2v gives a warning about network during conversion if source vmware guest's network is attched to standard switch but no entry 'ethernet0.networkName'

Additional info: