Uninstall app before testing the production build
Uninstall app before testing the production build

Summary:
Otherwise you may get the error `"Package <package_name> signatures do not match the previously installed version; ignoring!`

<details>
  Thanks for submitting a PR! Please read these instructions carefully:

  - [ ] Explain the **motivation** for making this change.
  - [ ] Provide a **test plan** demonstrating that the code is solid.
  - [ ] Match the **code formatting** of the rest of the codebase.
  - [ ] Target the `master` branch, NOT a "stable" branch.

  Please read the [Contribution Guidelines](https://github.com/facebook/react-native/blob/master/CONTRIBUTING.md) to learn more about contributing to React Native.
</details>

_What existing problem does the pull request solve?_

_A good test plan has the exact commands you ran and their output, provides screenshots or videos if the pull request changes UI or updates the website._
Closes https://github.com/facebook/react-native/pull/14577

Differential Revision: D5272060

Pulled By: AaaChiuuu

fbshipit-source-id: 23d88b8dddc4a7d8c6f58361a1cbcd8e6bb750d3

brentvatne/react-native,brentvatne/react-native,mironiasty/react-native,kesha-antonov/react-native,dikaiosune/react-native,hoastoolshop/react-native,janicduplessis/react-native,makadaw/react-native,negativetwelve/react-native,exponent/react-native,janicduplessis/react-native,hoangpham95/react-native,cpunion/react-native,myntra/react-native,makadaw/react-native,exponentjs/react-native,kesha-antonov/react-native,hoastoolshop/react-native,exponentjs/react-native,forcedotcom/react-native,mironiasty/react-native,pandiaraj44/react-native,hammerandchisel/react-native,javache/react-native,hoastoolshop/react-native,cdlewis/react-native,javache/react-native,arthuralee/react-native,thotegowda/react-native,myntra/react-native,makadaw/react-native,brentvatne/react-native,janicduplessis/react-native,frantic/react-native,brentvatne/react-native,javache/react-native,negativetwelve/react-native,myntra/react-native,arthuralee/react-native,exponent/react-native,doochik/react-native,doochik/react-native,Bhullnatik/react-native,janicduplessis/react-native,cdlewis/react-native,cdlewis/react-native,makadaw/react-native,pandiaraj44/react-native,kesha-antonov/react-native,cdlewis/react-native,jevakallio/react-native,forcedotcom/react-native,pandiaraj44/react-native,negativetwelve/react-native,mironiasty/react-native,farazs/react-native,javache/react-native,arthuralee/react-native,facebook/react-native,negativetwelve/react-native,Bhullnatik/react-native,jevakallio/react-native,exponentjs/react-native,ptmt/react-native-macos,doochik/react-native,dikaiosune/react-native,janicduplessis/react-native,myntra/react-native,hoastoolshop/react-native,cdlewis/react-native,brentvatne/react-native,facebook/react-native,pandiaraj44/react-native,dikaiosune/react-native,ptmt/react-native-macos,hoangpham95/react-native,facebook/react-native,hammerandchisel/react-native,rickbeerendonk/react-native,rickbeerendonk/react-native,exponentjs/react-native,doochik/react-native,rickbeerendonk/react-native,hoastoolshop/react-native,myntra/react-native,myntra/react-native,cpunion/react-native,formatlos/react-native,frantic/react-native,cpunion/react-native,ptmt/react-native-macos,javache/react-native,Bhullnatik/react-native,exponent/react-native,rickbeerendonk/react-native,kesha-antonov/react-native,dikaiosune/react-native,dikaiosune/react-native,thotegowda/react-native,exponentjs/react-native,exponent/react-native,farazs/react-native,cpunion/react-native,facebook/react-native,dikaiosune/react-native,brentvatne/react-native,farazs/react-native,farazs/react-native,hammerandchisel/react-native,jevakallio/react-native,hammerandchisel/react-native,exponentjs/react-native,negativetwelve/react-native,hoangpham95/react-native,rickbeerendonk/react-native,mironiasty/react-native,Bhullnatik/react-native,mironiasty/react-native,kesha-antonov/react-native,brentvatne/react-native,cdlewis/react-native,doochik/react-native,makadaw/react-native,farazs/react-native,hoastoolshop/react-native,forcedotcom/react-native,thotegowda/react-native,arthuralee/react-native,hammerandchisel/react-native,dikaiosune/react-native,pandiaraj44/react-native,makadaw/react-native,kesha-antonov/react-native,formatlos/react-native,negativetwelve/react-native,cdlewis/react-native,mironiasty/react-native,formatlos/react-native,dikaiosune/react-native,cdlewis/react-native,javache/react-native,farazs/react-native,arthuralee/react-native,Bhullnatik/react-native,hammerandchisel/react-native,ptmt/react-native-macos,doochik/react-native,pandiaraj44/react-native,formatlos/react-native,makadaw/react-native,janicduplessis/react-native,mironiasty/react-native,ptmt/react-native-macos,negativetwelve/react-native,exponentjs/react-native,Bhullnatik/react-native,facebook/react-native,javache/react-native,forcedotcom/react-native,thotegowda/react-native,kesha-antonov/react-native,forcedotcom/react-native,kesha-antonov/react-native,hammerandchisel/react-native,farazs/react-native,facebook/react-native,cpunion/react-native,kesha-antonov/react-native,cdlewis/react-native,jevakallio/react-native,jevakallio/react-native,doochik/react-native,hoastoolshop/react-native,pandiaraj44/react-native,exponent/react-native,brentvatne/react-native,rickbeerendonk/react-native,hoangpham95/react-native,Bhullnatik/react-native,facebook/react-native,pandiaraj44/react-native,jevakallio/react-native,frantic/react-native,thotegowda/react-native,formatlos/react-native,brentvatne/react-native,farazs/react-native,hoangpham95/react-native,hoangpham95/react-native,hoastoolshop/react-native,janicduplessis/react-native,mironiasty/react-native,cpunion/react-native,farazs/react-native,myntra/react-native,cpunion/react-native,thotegowda/react-native,ptmt/react-native-macos,facebook/react-native,janicduplessis/react-native,hammerandchisel/react-native,rickbeerendonk/react-native,hoangpham95/react-native,formatlos/react-native,negativetwelve/react-native,doochik/react-native,rickbeerendonk/react-native,hoangpham95/react-native,forcedotcom/react-native,mi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