fix stories

Author: kyledurand

polaris-react/src/components/Button/Button.stories.tsx

@@ -634,7 +634,7 @@ export function Split() {
   const [active, setActive] = React.useState(false);
   return (
     <div style={{height: '100px'}}>
-      <ButtonGroup segmented>
+      <ButtonGroup variant="segmented">
         <Button variant="primary">Save</Button>
 
         <div style={{width: '0px'}} />

polaris.shopify.com/pages/examples/button-split.tsx

@@ -7,7 +7,7 @@ function ButtonExample() {
   const [active, setActive] = React.useState(false);
   return (
     <div style={{height: '100px'}}>
-      <ButtonGroup segmented>
+      <ButtonGroup variant="segmented">
         <Button variant="primary">Save</Button>
         <div style={{width: '0px'}} />
         <Popover