yum module properly check for None config_file (#46641)

* yum module properly check for None config_file
* add conf_file test cases to yum integration tests

Signed-off-by: Adam Miller <admiller@redhat.com>

test/integration/targets/yum/tasks/yum.yml

@@ -120,6 +120,15 @@
     that:
         - "yum_result is successful"
 
+- name: install sos with state latest in check mode with config file param
+  yum: name=sos state=latest conf_file=/etc/yum.conf
+  check_mode: true
+  register: yum_result
+- name: verify install sos with state latest in check mode with config file param
+  assert:
+    that:
+        - "yum_result is changed"
+
 - name: install sos with state latest in check mode
   yum: name=sos state=latest
   check_mode: true
@@ -145,6 +154,15 @@
     that:
         - "not yum_result is changed"
 
+- name: install sos with state latest idempotence with config file param
+  yum: name=sos state=latest
+  register: yum_result
+- name: verify install sos with state latest idempotence with config file param
+  assert:
+    that:
+        - "not yum_result is changed"
+
+
 # Multiple packages
 - name: uninstall sos and bc
   yum: name=sos,bc state=removed