fixed dial transcribe is not able to receive final transcribe when closing the call (#1073)

* fixed dial transcribe is not able to received final transcribe when close call.

* wip

* fix review comment

* support call session delay detroy ep when current task is transcribe

* wip

* wip

* fixed review comments

* fixed review comments

lib/tasks/dequeue.js

@@ -3,8 +3,7 @@ const {TaskName, TaskPreconditions, DequeueResults, BONG_TONE} = require('../uti
 const Emitter = require('events');
 const bent = require('bent');
 const assert = require('assert');
-
-const sleepFor = (ms) => new Promise((resolve) => setTimeout(() => resolve(), ms));
+const { sleepFor } = require('../utils/helpers');
 
 const getUrl = (cs) => `${cs.srf.locals.serviceUrl}/v1/dequeue/${cs.callSid}`;