Disable role host_prep_tasks on controlplane upgrade

Disable role host_prep_tasks on controlplane upgrade

During the controlplane upgrade the host_prep_tasks are being
executed on the disable_upgrade_deployment roles too.

This sets the role specific host_prep_tasks to an empty list for
those roles during an upgrade, as executing them during the
controlplane upgrade (during -e
major-upgrade-composable-steps-docker.yaml) causes problems.

They will be executed as part of the non controller upgrade as they
are written to the stack outputs to be used as ansible playbooks
(see bug 1708115 for more info on this)

Change-Id: I42c963440b9b1e8222097c3d4e83ffcbe820886c
Closes-Bug: 1719604
(cherry picked from commit 684267a7a4fbff489f6324020289afbdcaaca8f5)