[7.x] [Metrics UI] Fix asynchronicity and error handling in Snapshot API (#70503)#70534

Zacqary merged 1 commit intoelastic:7.xelastic/kibana:7.xfrom

Zacqary:backport/7.x/pr-70503Zacqary/kibana:backport/7.x/pr-70503Copy head branch name to clipboard