Make APT pinning noop on distros that don't use APT

Change-Id: I7d9920468d9719158135d0a85d711341cf46868e

tasks/main.yml

@@ -17,7 +17,9 @@
   template:
     src: apt_pinned_packages.perf.j2
     dest: "/etc/apt/preferences.d/{{ apt_package_pinning_file_name }}"
-  when: apt_pinned_packages is defined
+  when:
+    - ansible_pkg_mgr == 'apt'
+    - apt_pinned_packages is defined
   tags:
     - apt-package-pinning
     - apt-install

tests/test.yml

@@ -23,12 +23,15 @@
       slurp:
         src: "/etc/apt/preferences.d/test.pref"
       register: preference_file
+      when: ansible_pkg_mgr == 'apt'
     - name: Read preference file
       set_fact:
         preference_contents: "{{ preference_file.content | b64decode }}"
+      when: ansible_pkg_mgr == 'apt'
     - name: Check pin files contents
       assert:
         that:
           - "'Pin: version 9.9.9-version' in preference_contents"
           - "'Pin: origin test-origin.org' in preference_contents"
           - "'Pin: release o=TestRelease' in preference_contents"
+      when: ansible_pkg_mgr == 'apt'