Allow json lists to be passed in via the pci-alias charm config option so that multiple aliases can be set

[teluka]

Currently, the nova-compute charm doesn't support json lists to be passed via the pci-alias parameter.

https://github.com/openstack/charm-nova-compute/blob/stable/20.10/hooks/nova_compute_context.py#L279

Nova.conf already support multiple alias fields since the following PR https://review.opendev.org/c/openstack/nova/+/592243/ got merged.

Nova.conf ref https://docs.openstack.org/nova/latest/configuration/config.html#pci.alias

Json lists are supported by nova-cloud-controller charm already https://github.com/openstack/charm-nova-cloud-controller/blob/stable/20.10/hooks/nova_cc_context.py#L398

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/charm-nova-compute/+/795411

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-nova-compute/+/795411
Committed: https://opendev.org/openstack/charm-nova-compute/commit/d51e010fcac6544775f95127c14f247532213d9b
Submitter: "Zuul (22348)"
Branch: master

commit d51e010fcac6544775f95127c14f247532213d9b
Author: Rodrigo Barbieri <email address hidden>
Date: Tue Jun 8 16:11:59 2021 -0300

    Port ncc pci-alias list fix to nova-compute

    Port of https://review.opendev.org/535350

    Fix for this bug already exists for
    nova-cloud-controller charm, therefore
    port it over to nova-compute.

    Closes-bug: #1921147
    Change-Id: I0c37d2bce3b195f5dc18111bb70a30de03b2bbc6
    func-test-pr: https://github.com/openstack-charmers/zaza-openstack-tests/pull/587

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/21.04
Review: https://review.opendev.org/c/openstack/charm-nova-compute/+/798288

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-nova-compute/+/798288
Committed: https://opendev.org/openstack/charm-nova-compute/commit/09c51160203bd2d803b63d2edfd47418f2f613cd
Submitter: "Zuul (22348)"
Branch: stable/21.04

commit 09c51160203bd2d803b63d2edfd47418f2f613cd
Author: Rodrigo Barbieri <email address hidden>
Date: Tue Jun 8 16:11:59 2021 -0300

    Port ncc pci-alias list fix to nova-compute

    Port of https://review.opendev.org/535350

    Fix for this bug already exists for
    nova-cloud-controller charm, therefore
    port it over to nova-compute.

    Closes-bug: #1921147
    Change-Id: I0c37d2bce3b195f5dc18111bb70a30de03b2bbc6
    (cherry picked from commit d51e010fcac6544775f95127c14f247532213d9b)