Enable optional chaining and nullish coalescing in flowconfig template (#20517)
Enable optional chaining and nullish coalescing in flowconfig template (#20517)

Summary:
Follow up to a9792ac4c8ee04f9832a99e95e1afebbb568d230 and #20516

This makes sure new projects typecheck properly since RN can use this syntax.
Pull Request resolved: https://github.com/facebook/react-native/pull/20517

Differential Revision: D9169268

Pulled By: TheSavior

fbshipit-source-id: f2b08598bdc6979931e987c9a275d75f08751754

myntra/react-native,pandiaraj44/react-native,hoangpham95/react-native,hoangpham95/react-native,hoangpham95/react-native,hoangpham95/react-native,javache/react-native,exponentjs/react-native,exponent/react-native,arthuralee/react-native,myntra/react-native,exponentjs/react-native,hammerandchisel/react-native,pandiaraj44/react-native,hammerandchisel/react-native,janicduplessis/react-native,javache/react-native,hammerandchisel/react-native,javache/react-native,myntra/react-native,pandiaraj44/react-native,javache/react-native,myntra/react-native,hammerandchisel/react-native,myntra/react-native,hoangpham95/react-native,arthuralee/react-native,janicduplessis/react-native,exponentjs/react-native,myntra/react-native,janicduplessis/react-native,myntra/react-native,hammerandchisel/react-native,exponentjs/react-native,facebook/react-native,exponentjs/react-native,hoangpham95/react-native,janicduplessis/react-native,hammerandchisel/react-native,janicduplessis/react-native,exponent/react-native,exponent/react-native,javache/react-native,exponentjs/react-native,hoangpham95/react-native,facebook/react-native,pandiaraj44/react-native,pandiaraj44/react-native,javache/react-native,facebook/react-native,facebook/react-native,exponent/react-native,myntra/react-native,arthuralee/react-native,arthuralee/react-native,janicduplessis/react-native,facebook/react-native,myntra/react-native,exponent/react-native,exponentjs/react-native,javache/react-native,exponent/react-native,javache/react-native,facebook/react-native,hammerandchisel/react-native,facebook/react-native,hammerandchisel/react-native,exponent/react-native,pandiaraj44/react-native,exponentjs/react-native,pandiaraj44/react-native,javache/react-native,janicduplessis/react-native,hoangpham95/react-native,pandiaraj44/react-native,arthuralee/react-native,facebook/react-native,exponent/react-native,janicduplessis/react-native,facebook/react-native