How to setup a virtual machine or virtual appliance in an IBM Cloud virtual private cloud (vpc) environment on a virtual server instance (vsi)? (nested Hypervisor)

This is a cheat sheet about, how to setup a virtual machine or virtual appliance in an IBM Cloud virtual private cloud (vpc) on a virtual server instance (vsi) with Red Hat Enterprise Linux 8 minimal install (RHEL8) as host operating system and a Ubuntu Linux operating system for the virtual machine or virtual appliance.