Merge branch 'ce-8317-operations-dashboard-usage-ping' into 'master'

Add dashboard scope for operations dashboard usage ping

See merge request gitlab-org/gitlab-ce!26727

app/models/user.rb

@@ -276,6 +276,7 @@ class User < ApplicationRecord
   scope :by_username, -> (usernames) { iwhere(username: Array(usernames).map(&:to_s)) }
   scope :for_todos, -> (todos) { where(id: todos.select(:user_id)) }
   scope :with_emails, -> { preload(:emails) }
+  scope :with_dashboard, -> (dashboard) { where(dashboard: dashboard) }
 
   # Limits the users to those that have TODOs, optionally in the given state.
   #