[k8s,ceph,docker] Apt repository filename cleanup

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

roles/deploy-env/tasks/containerd.yaml

@@ -36,7 +36,7 @@
   apt_repository:
     repo: deb [arch="{{ dpkg_architecture.stdout }}" signed-by=/etc/apt/trusted.gpg.d/docker.gpg] https://download.docker.com/linux/ubuntu "{{ ansible_distribution_release }}" stable
     state: present
-    filename: docker.list
+    filename: docker
 
 - name: Install docker packages
   apt:

roles/deploy-env/tasks/prerequisites.yaml

@@ -20,7 +20,7 @@
   apt_repository:
     repo: deb https://download.ceph.com/debian-reef/ "{{ ansible_distribution_release }}" main
     state: present
-    filename: ceph.list
+    filename: ceph
 
 - name: Add Kubernetes apt repository key
   apt_key:
@@ -31,7 +31,7 @@
   apt_repository:
     repo: "deb https://pkgs.k8s.io/core:/stable:/{{ kube_version_repo }}/deb/ /"
     state: present
-    filename: kubernetes.list
+    filename: kubernetes
 
 - name: Install necessary packages
   apt: