Update last_activity_on on browsing activity

Problem to solve

Instance admins frequently want to answer the question of "when was the last time a user used GitLab?" This is typically asked around true-up time or whenever an admin wants to groom out users who are no longer using GitLab at their organization.

The most common attributes for understanding this are last_activity_on and current_sign_in_at. They both have their drawbacks:

• last_activity_on updates on events but does not include logins or browsing activity.
• current_sign_in_at updates on a user logging into the UI, but does not include SSH activity and only updates on the login screen - if the client is logged in with a cookie, this does not update (despite the user using GitLab).

We should have one canonical source of truth for user activity, which should include a user logging into the UI and browsing around.

Proposal

• last_activity_on should include user browsing activity.

Links / references