LVM image build fails when VG name exists on build host

[Mark Goddard]

# Steps to reproduce

Build an image using an LVM recipe, e.g the following (taken from docs):

    - lvm:
        name: lvm
        pvs:
          - name: pv
            options: ["--force"]
            base: root

        vgs:
          - name: vg
            base: ["pv"]
            options: ["--force"]

        lvs:
          - name: lv_root
            base: vg
            size: 1800M

          - name: lv_tmp
            base: vg
            size: 100M

          - name: lv_var
            base: vg
            size: 500M

          - name: lv_log
            base: vg
            size: 100M

          - name: lv_audit
            base: vg
            size: 100M

          - name: lv_home
            base: vg
            size: 200M

In this case, if there is a volume group called vg on the build host, the build would fail. The actual error gets swallowed in the logs, but if you run the command manually, you get this:

    sudo vgcreate vg /dev/mapper/loop6p3 --force
    /dev/vg: already exists in filesystem

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/diskimage-builder/+/854427

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Mark Goddard <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/diskimage-builder/+/854427