Use blocks for macvlan tasks for each distribution (#8918)

For the code readability, this adds blocks for each distribution.

roles/network_plugin/macvlan/tasks/main.yml

@@ -27,7 +27,8 @@
   notify: Macvlan | restart network
   when: ansible_os_family in ["Debian"]
 
-- name: Macvlan | Install macvlan script on centos
+- block:
+  - name: Macvlan | Install macvlan script on centos
     copy:
       src: "{{ item }}"
       dest: /etc/sysconfig/network-scripts/
@@ -36,18 +37,17 @@
       mode: "0755"
     with_fileglob:
     - files/*
-  when: ansible_os_family == "RedHat"
 
-- name: Macvlan | Install post-up script on centos
+  - name: Macvlan | Install post-up script on centos
     copy:
       src: "files/ifup-local"
       dest: /sbin/
       owner: root
       group: root
       mode: "0755"
-  when: ansible_os_family == "RedHat" and enable_nat_default_gateway
+    when: enable_nat_default_gateway
 
-- name: Macvlan | Install network gateway interface on centos
+  - name: Macvlan | Install network gateway interface on centos
     template:
       src: "{{ item.src }}.j2"
       dest: "/etc/sysconfig/network-scripts/{{ item.dst }}"
@@ -57,23 +57,25 @@
     - {src: centos-routes-macvlan.cfg, dst: route-mac0 }
     - {src: centos-postup-macvlan.cfg, dst: post-up-mac0 }
     notify: Macvlan | restart network
+
   when: ansible_os_family == "RedHat"
 
-- name: Macvlan | Install service nat via gateway on Flatcar Container Linux
+- block:
+  - name: Macvlan | Install service nat via gateway on Flatcar Container Linux
     template:
       src: coreos-service-nat_ouside.j2
       dest: /etc/systemd/system/enable_nat_ouside.service
       mode: 0644
-  when: ansible_os_family in ["Flatcar", "Flatcar Container Linux by Kinvolk"] and enable_nat_default_gateway
+    when: enable_nat_default_gateway
 
-- name: Macvlan | Enable service nat via gateway on Flatcar Container Linux
+  - name: Macvlan | Enable service nat via gateway on Flatcar Container Linux
     command: "{{ item }}"
     with_items:
     - systemctl daemon-reload
     - systemctl enable enable_nat_ouside.service
-  when: ansible_os_family in ["Flatcar", "Flatcar Container Linux by Kinvolk"] and enable_nat_default_gateway
+    when: enable_nat_default_gateway
 
-- name: Macvlan | Install network gateway interface on Flatcar Container Linux
+  - name: Macvlan | Install network gateway interface on Flatcar Container Linux
     template:
       src: "{{ item.src }}.j2"
       dest: "/etc/systemd/network/{{ item.dst }}"
@@ -83,6 +85,7 @@
     - {src: coreos-interface-macvlan.cfg, dst: output.network }
     - {src: coreos-network-macvlan.cfg, dst: macvlan.network }
     notify: Macvlan | restart network
+
   when: ansible_os_family in ["Flatcar", "Flatcar Container Linux by Kinvolk"]
 
 - name: Macvlan | Install cni definition for Macvlan