fix(xy): stacked polarity (#1502) [38.1.x]#1526

nickofthyme merged 2 commits intoelastic:38.1.xelastic/elastic-charts:38.1.xfrom

nickofthyme:backport/38.1.x/pr-1502nickofthyme/elastic-charts:backport/38.1.x/pr-1502Copy head branch name to clipboard