2.7: adds 'success_msg' to valid args for assert module (#47030) (#47584)

* adds 'success_msg' to valid args for assert module (#47030)


(cherry picked from commit 0661f2f213)

* Add changelog

changelogs/fragments/47030-assert-add-success_msg-to-valid-args.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+    - assert - add 'success_msg' to valid args (https://github.com/ansible/ansible/pull/47030)

lib/ansible/plugins/action/assert.py

@@ -27,7 +27,7 @@ class ActionModule(ActionBase):
     ''' Fail with custom message '''
 
     TRANSFERS_FILES = False
-    _VALID_ARGS = frozenset(('fail_msg', 'msg', 'that'))
+    _VALID_ARGS = frozenset(('fail_msg', 'msg', 'success_msg', 'that'))
 
     def run(self, tmp=None, task_vars=None):
         if task_vars is None: