Purge legacy cleanup tasks from older than 1 year (#4450)

We don't need to support upgrades from 2 year old installs,
just from the last major version.

Also changed most retried tasks to 1s delay instead of longer.

roles/kubernetes/master/tasks/pre-upgrade.yml

@@ -1,29 +1,12 @@
 ---
-- name: "Pre-upgrade | etcd3 upgrade | see if old config exists"
-  command: "{{ bin_dir }}/etcdctl --peers={{ etcd_access_addresses }} ls /registry/minions"
-  environment:
-    ETCDCTL_API: 2
-    ETCDCTL_CERT_FILE: "{{ etcd_cert_dir }}/{{ kube_etcd_cert_file }}"
-    ETCDCTL_KEY_FILE: "{{ etcd_cert_dir }}/{{ kube_etcd_key_file }}"
-  register: old_data_exists
-  delegate_to: "{{groups['etcd'][0]}}"
-  changed_when: false
-  when: kube_apiserver_storage_backend == "etcd3"
-  failed_when: false
-
-- name: "Pre-upgrade | etcd3 upgrade | use etcd2 unless forced to etcd3"
-  set_fact:
-    kube_apiserver_storage_backend: "etcd2"
-  when: old_data_exists.rc == 0 and not force_etcd3|bool
-
-- name: "Pre-upgrade | Delete master manifests"
+- name: "Pre-upgrade | Delete master manifests if etcd secrets changed"
   file:
     path: "/etc/kubernetes/manifests/{{item}}.manifest"
     state: absent
   with_items:
     - ["kube-apiserver", "kube-controller-manager", "kube-scheduler"]
   register: kube_apiserver_manifest_replaced
-  when: (secret_changed|default(false) or etcd_secret_changed|default(false))
+  when: etcd_secret_changed|default(false)
 
 - name: "Pre-upgrade | Delete master containers forcefully"
   shell: "docker ps -af name=k8s_{{item}}* -q | xargs --no-run-if-empty docker rm -f"
@@ -31,6 +14,6 @@
     - ["kube-apiserver", "kube-controller-manager", "kube-scheduler"]
   when: kube_apiserver_manifest_replaced.changed
   register: remove_master_container
-  retries: 4
+  retries: 10
   until: remove_master_container.rc == 0
-  delay: 5
+  delay: 1