This upgrades Kubernetes version in airshipctl to v1.21.2
Depends on https://review.opendev.org/c/airship/image-builder/+/812013/
https: //github.com/airshipit/airshipctl/issues/589
Change-Id: I30ef2543d91f574e73a555bf67ab7ec2764a4411
Signed-off-by: diwakar thyagaraj <dt241s@att.com>