Add validation to check if a reboot of a node is necessary

For Upgrade usage, this validation will check with yum-utils
if a reboot is needed by some core packages according to:
https://access.redhat.com/solutions/27943

Change-Id: Ib0ec55bfb4614b1415ab61a0077c34f4d147d43d

doc/source/roles/role-check_reboot.rst

@@ -0,0 +1,6 @@
+============
+check_reboot
+============
+
+.. ansibleautoplugin::
+   :role: roles/check_reboot

playbooks/check-reboot.yaml

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+---
+- hosts: all
+  gather_facts: true
+  vars:
+    metadata:
+      name: Verify if a reboot is necessary with yum-utils
+      description: |
+        This validation checks if a reboot is necessary with yum-utils
+        with the option: needs-restarting -r
+      groups:
+        - pre-upgrade
+        - pre-update
+        - post-upgrade
+        - post-update
+      categories:
+        - os
+        - kernel
+        - system
+      products:
+        - tripleo
+  roles:
+    - check_reboot

roles/check_reboot/defaults/main.yaml

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+---
+fail_if_reboot: true
+no_reboot_message: "Reboot should not be necessary."

roles/check_reboot/tasks/main.yaml

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+---
+- name: Make sure yum-utils is installed
+  become: true
+  package:
+    name: yum-utils
+
+- name: Check if reboot is required
+  register: command_output
+  shell: |
+    needs-restarting -r
+
+- name: Fail if core packages need reboot
+  fail:
+    msg: |
+          {{ command_output.stdout }}
+  when:
+    - no_reboot_message not in command_output.stdout
+    - fail_if_reboot