[calico] don't enable ipip encapsulation by default and use vxlan in CI (#8434)

* [calico] make vxlan encapsulation the default

* don't enable ipip encapsulation by default
* set calico_network_backend by default to vxlan
* update sample inventory and documentation

* [CI] pin default calico parameters for upgrade tests to ensure proper upgrade

* [CI] improve netchecker connectivity testing

* [CI] show logs for tests

* [calico] tweak task name

* [CI] Don't run the provisioner from vagrant since we run it in testcases_run.sh

* [CI] move kube-router tests to vagrant to avoid network connectivity issues during netchecker check

* service proxy mode still fails connectivity tests so keeping it manual mode

* [kube-router] account for containerd use-case

roles/network_plugin/calico/tasks/check.yml

@@ -11,8 +11,6 @@
     that:
       - "calico_network_backend in ['bird', 'vxlan', 'none']"
     msg: "calico network backend is not 'bird', 'vxlan' or 'none'"
-  when:
-    - calico_network_backend is defined
 
 - name: "Check ipip and vxlan mode defined correctly"
   assert:

roles/network_plugin/calico/tasks/install.yml

@@ -194,7 +194,7 @@
     - inventory_hostname == groups['kube_control_plane'][0]
     - 'calico_conf.stdout == "0"'
 
-- name: Calico | Configure calico ipv6 network pool (version >= v3.3.0)
+- name: Calico | Configure calico ipv6 network pool
   command:
     cmd: "{{ bin_dir }}/calicoctl.sh apply -f -"
     stdin: >