Bump Yarn cache key and fix JavaScript tests (#27343)
Bump Yarn cache key and fix JavaScript tests (#27343)

Summary:
Trivial - bumping the cache key used by yarn should help unblock the JS test failures on master.

Changelog:
[General] [Fixed] - Bump Yarn cache key in Circle CI config to address JS test failures

Pull Request resolved: https://github.com/facebook/react-native/pull/27343

Differential Revision: D18717521

Pulled By: hramos

fbshipit-source-id: f241a6da410881c8c50c42993338f6ca4b6dc4f2

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