Add python-rhsm-certificates package to iso

[praveenkumar]

python-rhsm-certificates package provide /etc/rhsm/ca/redhat-uep.pem which is required to get images from registry.access.redhat.com without this package now docker block to pull the images from redhat registry.

$ docker pull registry.access.redhat.com/jboss-datagrid-6/datagrid65-openshift@sha256:d7108be45859a46b0075f95246d3f16669c4cd471dbf43196389524ec568d220
Trying to pull repository registry.access.redhat.com/jboss-datagrid-6/datagrid65-openshift ... 
open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory

$ ls -l /etc/docker/certs.d/registry.access.redhat.com/
total 0
lrwxrwxrwx. 1 root root 27 Mar 26 05:07 redhat-ca.crt -> /etc/rhsm/ca/redhat-uep.pem

# yum whatprovides "/etc/rhsm/ca/redhat-uep.pem"          
python-rhsm-certificates-1.19.10-1.el7_4.x86_64 : Certificates required to communicate with a Red Hat Unified Entitlement Platform
Repo        : updates
Matched from:
Filename    : /etc/rhsm/ca/redhat-uep.pem

[LalatenduMohanty]

Resolved via #236