Generally, if you want to bring your own physical core license to the cloud, you need to reserve dedicated hardware (called
Sole-tenant nodes), and the discussion here is about premium OS licenses (not free operating systems). Now migrating from a cloud service to another is a bit different as usually Cloud Providers utilizes a concept called "Pay As You Go". Meaning you get billed per usage. I found this
document that explains License differences that should help.
One way to verify the license is by describing the boot disk using this
command in
cloudshell. Example (replace instance name and zone):
gcloud compute disks describe instanceName --zone us-central1-a | grep licenses
If the BYOS license is not applied, you may try posting on
serverfault.com for technical help applying it. However, you may try to use
this method making an existing image bootable and forcing the license, as your image is already imported. I hope this helps.