Summary:
PlatformColorExample RNTester page crashes when running on platforms other than iOS/Android.
Changed some very minor logic to take into account that platforms other than iOS/Android exist.
## Changelog
[Internal] [Fixed] - PlatformColorExample RNTester page crashes when running on platforms other than iOS/Android.
Pull Request resolved: https://github.com/facebook/react-native/pull/29120
Reviewed By: sahrens
Differential Revision: D22109188
Pulled By: TheSavior
fbshipit-source-id: 853bea0ac4ea5c67f35d89d1a2bf55f5c89823b4
Andrew Coates (REDMOND)
f8c68bf358