Move package description to global variable and replace with it.

[chkumar246]

Currently, in most of the RDO packages, package description is copied at all the subpackage.
It looks redundant. It would be good if we can move replace common description used under all
subpackage to a variable and use that variable and replace the common description
with it.

How to reproduce:

1. Clone openstack-nova spec file git clone https://github.com/rdo-packages/nova-distgit
2. Go to nova-distgit and open openstack-nova.spec in editor
3. We need to fix all the redundant contents under %description section for all subpackages in the given spec file.

How to fix:

1. Define a common variable %global common_desc
2. Replace go to %description section of all subpackage and replace common content
   with %{common_desc}
3. Add the changes file, commit it and send a Gerrit review.
4. Please cross checklist
   before sending Gerrit Review.

Here is the example spec file where it is fixed: https://github.com/rdo-packages/os-traits-distgit/blob/rpm-master/python-os-traits.spec

Below is the list of packages which need same fixes:

• openstack-nova
• openstack-glance
• openstack-cinder
• openstack-swift
• openstack-neutron
• openstack-keystone

Mentor: chandankumar
Note: Pick one of the package and comment in the comment box with review link.

[rarguello]

openstack-nova Gerrit review: https://review.rdoproject.org/r/#/c/7731/

[rarguello]

openstack-glance Gerrit review: https://review.rdoproject.org/r/#/c/7732/

[rarguello]

openstack-cinder Gerrit review: https://review.rdoproject.org/r/#/c/7733/

[rarguello]

openstack-swift Gerrit review: https://review.rdoproject.org/r/#/c/7734/

[rarguello]

openstack-neutron Gerrit review: https://review.rdoproject.org/r/#/c/7735/

[rarguello]

openstack-keystone Gerrit review: https://review.rdoproject.org/r/#/c/7736/

[snecklifter]

@rarguello cool, I'm doing this for python-senlinclient but if you wanted to do this for senlin itself, which just landed, that would be great!

[snecklifter]

I'll have a look and see if this needs doing anywhere else. I suspect the answer is everywhere...