In order to optimise the distro package installation
process the list of packages to install is prepared
for the host, then installed by passing the package
task the full list instead of using a loop.
Conflicts:
>------tasks/keystone_install.yml
>------vars/main.yml
Change-Id: Ia5c8f31470f0f917ee556ca1157b9191da9d0d2c
(cherry picked from commit 77691078b7)
d51b90e576