[RBAC] Adjust system:kube-dns rules for configmaps

Without additional rules we are getting the following error in
contrainer:
E0205 09:11:38.505998       1 dns.go:183] Error getting initial
ConfigMap: configmaps "kube-dns" is forbidden: User
"system:serviceaccount:kube-system:kube-dns" cannot get configmaps in
the namespace "kube-system", starting with default values

We doesn't have configmap for kubedns atm, but this patch will save
some time for those who will create configmap for any other purposes.

Change-Id: I1c0cafab735059cb66cd892b9ecfceb29469fd44
2 files changed