Target the SectionList viewability item by test ID (#58991)

Summary:
Pull Request resolved: #58991

Locate `Brownie` by its existing `testID` in the horizontal SectionList viewability flow rather than its rendered text. Keep the scrolling parameters and viewability callback assertions unchanged.

Changelog: [Internal]

Differential Revision: D124664726

fbshipit-source-id: 1b0156cd360b894c1a627f2d7d620c3c7986b372

Author: Abbondanzo

packages/rn-tester/.maestro/sectionlist-viewability.yml

@@ -30,7 +30,7 @@ appId: ${APP_ID} # iOS: com.meta.RNTester.localDevelopment | Android: com.facebo
     timeout: 30000
 - scrollUntilVisible:
     element:
-      text: 'Brownie'
+      id: 'Brownie'
     direction: RIGHT
     speed: 60
     visibilityPercentage: 50