[6.x] Convert usage of notify.error to toastNotifications.addDanger for string messages (#22243)#22309

cjcenizal merged 1 commit intoelastic:6.xelastic/kibana:6.xfrom

cjcenizal:backport/6.x/pr-22243cjcenizal/kibana:backport/6.x/pr-22243Copy head branch name to clipboard