Export the hmr plugin directly
Export the hmr plugin directly

Summary: This will allow to configure the HMR plugin directly from `.babelrc` again, instead of having to create a bridge file: https://github.com/rafeca/metro-sample-app/blob/master/metro-babel7-plugin-react-transform.js#L3

Reviewed By: davidaurelio

Differential Revision: D7707314

fbshipit-source-id: 4c5612e1e5d27874807f2dce50d99ec0f6354bbc

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