Fold kubernetes-apps/network_plugin into network_plugin (#12506)

For what I can see, there is no reason for the split, and it makes
things confusing.

roles/network_plugin/flannel/tasks/main.yml

@@ -19,3 +19,20 @@
   register: flannel_node_manifests
   when:
     - inventory_hostname == groups['kube_control_plane'][0]
+
+- name: Flannel | Start Resources
+  kube:
+    name: "{{ item.item.name }}"
+    namespace: "kube-system"
+    kubectl: "{{ bin_dir }}/kubectl"
+    resource: "{{ item.item.type }}"
+    filename: "{{ kube_config_dir }}/{{ item.item.file }}"
+    state: "latest"
+  with_items: "{{ flannel_node_manifests.results }}"
+  when: inventory_hostname == groups['kube_control_plane'][0] and not item is skipped
+
+- name: Flannel | Wait for flannel subnet.env file presence
+  wait_for:
+    path: /run/flannel/subnet.env
+    delay: 5
+    timeout: 600