Verify that usage ping is default on

Overview

In the 2019-06-04 product meeting, @joshlambert pulled up a new GitLab instance from Omnibus (11.6.5, I believe) and noticed that the usage ping defaulted to off.

Proposal

• Validate that usage ping defaults to on. An instance shouldn't be required to opt in to enable usage ping, the desired experience is for a CE/EE instance to specifically opt-out via gitlab.rb or via the admin panel.
• Verify that we have sufficient testing in place to ensure that usage ping remains on by default from release to release.