title: app engine deployment through cloud shell hangs without error
body: <p>I am deploying a app engine application through cloud shell. I have deployed it a lot of times, but currently when ever I deploy it i gets hanged at the below position and nothing happens:</p>
  <pre><code>myname@cloudshell:~stackdriver-metrics-export/list_metrics (my-project)$ gcloud app deploy
  Services to deploy:
  descriptor:      [/home/myname/stackdriver-metrics-export/list_metrics/app.yaml]
  source:          [/home/myname/stackdriver-metrics-export/list_metrics]
  target project:  [my-project]
  target service:  [list-metrics]
  target version:  [20200703t225313]
  target url:      [http://list-metrics.my-project.uc.r.appspot.com]
  Do you want to continue (Y/n)?  Y
  Beginning deployment of service [list-metrics]...
  </code></pre>
  <p>// it gets stuck here and nothing happens afterwards I even restarted cloudshell lot of times but the same result, there is no change in the cursor position also. No error is also thrown</p>
  <p>Please help me as i am new to cloud shell and google cloud.</p>