Refactor use of include_vars

Use a first_found lookup instead of a with_first_found loop so that
the 'paths' parameter can be used.

This ensures that only vars from the role are included, and not vars
from a parent calling role. This can happen when a parent role has
a higher priority vars file available for inclusion than the role
it calls.

Change-Id: I4d4a51ca805857d56f108c3717beaa5648f86ccb

tasks/main.yml

@@ -14,15 +14,18 @@
 # limitations under the License.
 
 - name: Gather variables for each operating system
-  include_vars: "{{ item }}"
-  with_first_found:
-    - files:
+  include_vars: "{{ lookup('first_found', params) }}"
+  vars:
+    params:
+      files:
         - "{{ ansible_facts['distribution'] | lower }}-{{ ansible_facts['distribution_version'] | lower }}.yml"
         - "{{ ansible_facts['distribution'] | lower }}-{{ ansible_facts['distribution_major_version'] | lower }}.yml"
         - "{{ ansible_facts['os_family'] | lower }}-{{ ansible_facts['distribution_major_version'] | lower }}.yml"
         - "{{ ansible_facts['distribution'] | lower }}.yml"
+        - "{{ ansible_facts['os_family'] | lower }}-{{ ansible_facts['distribution_version'].split('.')[0] }}.yml"
         - "{{ ansible_facts['os_family'] | lower }}.yml"
-      skip: true
+      paths:
+        - "{{ role_path }}/vars"
   tags:
     - always