[6.x] Fix bug in xpackInfo in which keys were being camel-cased during refresh but not init (#29304)#29568

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

cjcenizal:backport/29304/6.xcjcenizal/kibana:backport/29304/6.xCopy head branch name to clipboard