Fix UIExplorer headings accessibility

packages/website/storybook/ui-explorer/AppText.js

@@ -14,12 +14,12 @@ class AppText extends React.PureComponent {
   };
 
   render() {
-    const { style, ...rest } = this.props;
+    const { accessibilityRole, style, ...rest } = this.props;
     const isInAParentText = this.context;
     return (
       <Text
         {...rest}
-        accessibilityRole={rest.href ? 'link' : undefined}
+        accessibilityRole={rest.href ? 'link' : accessibilityRole}
         style={[!isInAParentText && styles.baseText, style, rest.href && styles.link]}
       />
     );

packages/website/storybook/ui-explorer/Section.js

@@ -8,7 +8,11 @@ import AppText from './AppText';
 import React from 'react';
 import { StyleSheet, View } from 'react-native';
 
-const SectionTitle = ({ children }) => <AppText style={styles.sectionTitle}>{children}</AppText>;
+const SectionTitle = ({ children }) => (
+  <AppText accessibilityRole="heading" aria-level="2" style={styles.sectionTitle}>
+    {children}
+  </AppText>
+);
 
 const Section = ({ children, title }) => (
   <View>

packages/website/storybook/ui-explorer/UIExplorer.js

@@ -10,7 +10,11 @@ import insertBetween from './insertBetween';
 import React from 'react';
 import { StyleSheet, View } from 'react-native';
 
-const Title = ({ children }) => <AppText style={styles.title}>{children}</AppText>;
+const Title = ({ children }) => (
+  <AppText accessibilityRole="heading" style={styles.title}>
+    {children}
+  </AppText>
+);
 
 export const Description = ({ children }) => (
   <AppText style={styles.description}>