Fix some typing annotations
Fix some typing annotations

Summary: Export font weight type to use in typing

Reviewed By: panagosg7

Differential Revision: D17128236

fbshipit-source-id: baf9d5e5c5fa0b8aad4cf29ea94430adfe1e8b5f

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