fixed source path discovery for unarchive in roles

fixes #11943

lib/ansible/plugins/action/unarchive.py

@@ -60,6 +60,9 @@ class ActionModule(ActionBase):
             # FIXME: the original file stuff needs to be reworked
             if '_original_file' in task_vars:
                 source = self._loader.path_dwim_relative(task_vars['_original_file'], 'files', source)
+            else:
+                if self._task._role is not None:
+                    source = self._loader.path_dwim_relative(self._task._role._role_path, 'files', source)
                 else:
                     source = self._loader.path_dwim(source)