Deprecated v0.1 and v1beta1 endpoints of the App Engine and Cloud Functions metadata server

[rubensedanoc]

After September 30, 2020, requests to the v0.1 and v1beta1 endpoints will no longer be supported, and may return HTTP 404 NOT FOUND responses. As a result, before September 30, 2020, you will need to update your requests to use the v1 endpoint, which was available starting in 2016.