Replaced app identity lib with env vars (#1207)
Replaced app identity lib with env vars (#1207)

* Removed app identity lib for env vars

* Implemented requested changes

* changes with the use of UNIT_TEST_MODE

* Reverted chromedash-metadata.js
GoogleChrome/chromium-dashboard,GoogleChrome/chromium-dashboard,GoogleChrome/chromium-dashboard,GoogleChrome/chromium-dashboard,GoogleChrome/chromium-dashboard