Use symbolic link for kube admin config

Use symbolic link for kube admin config instead of copy and maintain
two identical file. `/root/.kube/config` is now a symbolic link of file
`/etc/kubernetes/admin.conf`. This will prevent any unsync file issue.

Sem-Ver: bugfix
Change-Id: I2b4b611b5724fdc5fe9ef213e30f2838c1f294b2
2 files changed