Protect group overview usage ping w/ feature flag

user_preferences key is includes into system usage
data only if group_overview_security_dashboard
feature flag is enabled; see
https://gitlab.com/gitlab-org/gitlab-ee/issues/7048

lib/gitlab/usage_data.rb

@@ -93,8 +93,11 @@ module Gitlab
           }
           .merge(services_usage)
           .merge(approximate_counts)
-          .merge(user_preferences: user_preferences_usage)
-        }
+        }.tap do |data|
+          if Feature.enabled?(:group_overview_security_dashboard)
+            data[:counts][:user_preferences] = user_preferences_usage
+          end
+        end
       end
       # rubocop: enable CodeReuse/ActiveRecord
 

spec/lib/gitlab/usage_data_spec.rb

@@ -128,6 +128,11 @@ describe Gitlab::UsageData do
       ))
     end
 
+    it 'does not gather user preferences usage data when the feature is disabled' do
+      stub_feature_flags(group_overview_security_dashboard: false)
+      expect(subject[:counts].keys).not_to include(:user_preferences)
+    end
+
     it 'gathers projects data correctly' do
       count_data = subject[:counts]