singleDialer should create ConfirmCallSession with correct tmpFiles (#1357)

lib/utils/place-outdial.js

@@ -403,7 +403,7 @@ class SingleDialer extends Emitter {
         tasks,
         rootSpan: this.rootSpan,
         req: this.req,
-        tmpFiles: cs.tmpFiles,
+        tmpFiles: this.tmpFiles,
       });
       await cs.exec();