Metrics fail to get detected unless they have an environment tag

With support in https://gitlab.com/gitlab-org/gitlab-ce/issues/35267 to have specific variable substation, this has opened up a number of possibilities like https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13438.

Unfortunately the Service Integration reports are showing the metrics as missing environment variables.

Good charts: Screen_Shot_2017-08-09_at_5.05.32_PM

But no "detected metrics" for nginx ingress: Screen_Shot_2017-08-09_at_5.01.42_PM