Add custom-dashboard-base-path to dashboard data

app/helpers/environments_helper.rb

@@ -95,7 +95,8 @@ module EnvironmentsHelper
       'empty-loading-svg-path'           => image_path('illustrations/monitoring/loading.svg'),
       'empty-no-data-svg-path'           => image_path('illustrations/monitoring/no_data.svg'),
       'empty-no-data-small-svg-path'     => image_path('illustrations/chart-empty-state-small.svg'),
-      'empty-unable-to-connect-svg-path' => image_path('illustrations/monitoring/unable_to_connect.svg')
+      'empty-unable-to-connect-svg-path' => image_path('illustrations/monitoring/unable_to_connect.svg'),
+      'custom-dashboard-base-path'       => Metrics::Dashboard::CustomDashboardService::DASHBOARD_ROOT
     }
   end
 end

spec/helpers/environments_helper_spec.rb

@@ -40,7 +40,8 @@ describe EnvironmentsHelper do
         'validate-query-path' => validate_query_project_prometheus_metrics_path(project),
         'custom-metrics-available' => 'true',
         'alerts-endpoint' => project_prometheus_alerts_path(project, environment_id: environment.id, format: :json),
-        'prometheus-alerts-available' => 'true'
+        'prometheus-alerts-available' => 'true',
+        'custom-dashboard-base-path' => Metrics::Dashboard::CustomDashboardService::DASHBOARD_ROOT
       )
     end