This commit adds the kubernetes plugin kubectl cert manager to the iso.
This is used to convert old v1alpha2 and v1alpha3 cert manager
resources to v1 during a system upgrade. The plugin is not required
for debian because there are no old cert manager resources to convert.
Test Cases:
PASS: Convert our default DC certificates and issuers using
kubectl cert manager
Change-Id: I59f1b0e4d5d6ece1ccef43fee1acacd7b7e44efd
Story: 2009837
Task: 45372
Signed-off-by: Jerry Sun <jerry.sun@windriver.com>