Support fbt for accessibilityValue
Support fbt for accessibilityValue

Summary: Changelog: [Internal] - Change accessibilityValue.text type to allow for Stringish type

Reviewed By: yungsters

Differential Revision: D31577860

fbshipit-source-id: af12505794037a68850a16ce139359e2f8a879e4

javache/react-native,janicduplessis/react-native,facebook/react-native,facebook/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,janicduplessis/react-native,facebook/react-native,janicduplessis/react-native,janicduplessis/react-native,facebook/react-native,facebook/react-native,facebook/react-native,janicduplessis/react-native,facebook/react-native,javache/react-native,javache/react-native,facebook/react-native,javache/react-native