Chore: Move to ubuntu2004-docker

Chore: Move to ubuntu2004-docker

jjb/sdc/sdc-sdc-distribution-client.yaml
jjb/sdc/sdc-sdc-docker-base.yaml
jjb/sdc/sdc-sdc-helm-validator.yaml
jjb/sdc/sdc-sdc-workflow-designer.yaml
jjb/sdc/sdc.yaml
jjb/sdnc/sdnc-apps.yaml
jjb/sdnc/sdnc-oam.yaml
jjb/so/so-adapters-so-cnf-adapter.yaml
jjb/so/so-adapters-so-etsi-sol003-adapter.yaml
jjb/so/so-adapters-so-etsi-sol005-adapter.yaml
jjb/so/so-adapters-so-nssmf-adapter.yaml
jjb/so/so-adapters-so-oof-adapter.yaml
jjb/so/so-so-admin-cockpit.yaml
jjb/so/so-so-etsi-nfvo.yaml
jjb/so/so.yaml

Issue-ID: CIMAN-33
Signed-off-by: Bengt Thuree <bthuree@linuxfoundation.org>
Change-Id: Idc4566f2388c63b6962dc8250fbea5f13a7e6b09