remove createReactClass from the IntegrationTests/ReactContentSizeUpdateTest.js (#21622)
remove createReactClass from the IntegrationTests/ReactContentSizeUpdateTest.js (#21622)

Summary:
Related to #21581 .
Removed createReactClass from the IntegrationTests/ReactContentSizeUpdateTest.js

 - [x] npm run prettier
 - [x] npm run flow-check-ios
 - [x] npm run flow-check-android

[GENERAL] [ENHANCEMENT] [IntegrationTests/ReactContentSizeUpdateTest.js] - remove createReactClass dependency
Pull Request resolved: https://github.com/facebook/react-native/pull/21622

Reviewed By: TheSavior

Differential Revision: D10302181

Pulled By: RSNara

fbshipit-source-id: 97b955070deb7a244f335ad609f26ffc07578c01

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