GONRG-4846: Services can't start without env variable GOOGLE_CLOUD_PROJECT

https://jiraeu.epam.com/browse/GONRG-4846

* updated core-lib-gcp to 0.15.0-rc3
4 jobs for !266 with gcp/bugfix/core-lib-gcp-update in 39 minutes and 13 seconds (queued for 1 second)
latest merge request