/usr/share/gocode/src/golang.org/x/oauth2/google/testdata/gcloud/properties is in golang-golang-x-oauth2-google-dev 0.0~git20161103.0.36bc617-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | [core]
account = bar@example.com
|