kubespray

* Add KubeSchedulerConfiguration for k8s 1.19 and up

With release of version 1.19.0 of kubernetes KubeSchedulerConfiguration
was graduated to beta. It allows to extend different stages of
scheduling with profiles. Such effect is achieved by using plugins and
extensions.

This patch adds KubeSchedulerConfiguration for versions 1.19 and later.
Configuration is set to k8s defaults or to kubespray vars. Moving those
defaults to new vars will be done in following patch.

Signed-off-by: Maciej Wereski <m.wereski@partner.samsung.com>

* KubeSchedulerConfiguration: add defaults

Signed-off-by: Maciej Wereski <m.wereski@partner.samsung.com>