The prerequisites and containerd tasks that add the Kubernetes,
Ceph, and Docker repos to apt list the filenames as
kubernetes.list, ceph.list, and docker.list, which results in the
files created under /etc/apt/sources.list.d being named with
'.list.list' extensions. This change simply removes the redundant
'.list' from the filenames to clean that up.
Change-Id: I3672873149d137ad89c176cabad4c64dcff2bfee
646180ea0e