Kayobe has a role to disable SELinux. Some systems do not have SELinux
installed (this can be reproduced by removing the selinux-policy package
and removing /etc/selinux/config). This causes the selinux
Ansible module to fail, since it can't write to /etc/selinux/config:
Please install SELinux-policy package, if this package is not
installed previously.
This change fixes the issue by only disabling SELinux if the config file
exists.
Change-Id: I25c7282c1e8dcdee3e7feddef9d66ca5beeb1bce
Story: 2007704
Task: 39820
09754df82f