Add E2E tests for Text boxShadow and textWithLinkRole (#55961)

Summary:
Pull Request resolved: #55961

Add E2E tests for 2 uncovered Text examples in RNTester:
- boxShadow: screenshot test using existing testID 'text-box-shadow'
- textWithLinkRole: interaction test that screenshots before and after pressing
  the link (which changes its color from teal to red)

Source changes:
- Added testID="text-with-link-role" to root View in TextWithLinkRoleExample
- Added testID="text-link-role-link" to the first link Text element
- Added useState to toggle link color on press (teal -> red)

Reviewed By: cortinico

Differential Revision: D95359182

fbshipit-source-id: c823b1c0c071aed0750b3cf3f2d7d6b88da87573

Author: NickGerleman

packages/rn-tester/js/examples/Text/TextSharedExamples.js

@@ -194,11 +194,17 @@ component RtlAndInlineViewsExample() {
 }
 
 component TextWithLinkRoleExample() {
-  const handlePress = () => console.log('Link Press');
+  const [pressed, setPressed] = useState(false);
+  const handlePress = () => setPressed(true);
+  const linkColor = pressed ? 'red' : 'teal';
 
   return (
-    <View>
-      <Text role="link" style={styles.link} onPress={handlePress}>
+    <View testID="text-with-link-role">
+      <Text
+        role="link"
+        style={[styles.link, {color: linkColor}]}
+        onPress={handlePress}
+        testID="text-link-role-link">
         Link Text
       </Text>