Remove sleep and use iPhone 7 in devices (#38356)

js/tests/lt-local.js

@@ -19,6 +19,7 @@ if (process.env.LAMBDATEST === 'true') {
   (async () => {
     try {
       await tunnelInstance.start(tunnelArguments)
+      await new Promise(res => setTimeout(res, 5000))
     } catch (error) {
       console.log(error.message)
     }