RBAC: Add system:nodes group to system:node

Why:
In our setup we need to authorize nodes via using the system:nodes group
This used to work up to 1.7, but starting with 1.8 this is no longer
automatically being added. Add it to our rules

What:
Add a cluster role binding for system:nodes group to system:node cluster
role

Bug: T239835
Change-Id: I1454cdd5d2aa59aff56d20de341eb7e6497acac7