Update Flannel manifests, install script and version (0.12) + fix tests scripts (#5937)

* Add CI_TEST_VARS to tests

* Update flannel to 0.12.0 (with new manifests) and disable tx/rx
offloading in networking test

roles/network_plugin/flannel/tasks/main.yml

@@ -9,3 +9,19 @@
   register: flannel_node_manifests
   when:
     - inventory_hostname in groups['kube-master']
+
+- name: Flannel | Set CNI directory permissions
+  file:
+    path: /opt/cni/bin
+    state: directory
+    owner: kube
+    recurse: true
+    mode: 0755
+  register: cni_bin_dir
+
+- name: Flannel | Copy CNI plugins
+  unarchive:
+    src: "{{ local_release_dir }}/cni-plugins-linux-{{ image_arch }}-{{ cni_version }}.tgz"
+    dest: "/opt/cni/bin"
+    mode: 0755
+    remote_src: yes