Add secondary sort to getJourneySteps query (#82281) (#82304)

Fixes ordering bug

Author: Kerry350

x-pack/plugins/uptime/server/lib/requests/get_journey_steps.ts

@@ -35,7 +35,7 @@ export const getJourneySteps: UMElasticsearchQueryFn<GetJourneyStepsParams, Ping
           ],
         },
       },
-      sort: [{ '@timestamp': { order: 'asc' } }],
+      sort: [{ 'synthetics.step.index': { order: 'asc' } }, { '@timestamp': { order: 'asc' } }],
       _source: {
         excludes: ['synthetics.blob'],
       },