Comment 13 for bug 1762421

Reviewed: https://review.openstack.org/603383
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-galera_server/commit/?id=943b0360a7c85e157d0c24abe47215462395ae16
Submitter: Zuul
Branch: stable/rocky

commit 943b0360a7c85e157d0c24abe47215462395ae16
Author: Jesse Pretorius <email address hidden>
Date: Mon Sep 17 20:25:02 2018 +0100

    Revisit conflicting package removal

    In https://review.openstack.org/534819 we introduced the removal
    of conflicting packages from the targeted host, but then we deleted
    the list for RedHat in https://review.openstack.org/578844 because
    yum kept removing and re-adding the same packages.

    In https://review.openstack.org/603205 we solve the issue properly
    given that yum is case-insensitive, and the root cause of the repeat
    remove/install.

    As such, in this patch, we restore the removal of conflicting
    packages for RedHat in a different way. Each of the package removal
    tasks are moved into the tasks specific to each package manager so
    that each can be handled differently.

    Change-Id: I70fbfa6eff8796713c6bec32319382273f8281f8
    Related-Bug: #1762421
    Related-Bug: #1742206
    (cherry picked from commit 72f402d3e969c94754ade02953d2c94ce541b25e)