Summary:
This PR adds support for the `shadowColor` style on Android.
This is possible as of Android P using the `setOutlineAmbientShadowColor` and `setOutlineSpotShadowColor` View methods. The actual rendered color is a multiplication of the color-alpha, shadow-effect and elevation-value.
## Changelog
`[Android] [Added] - Add support for shadowColor on API level >= 28`
Pull Request resolved: https://github.com/facebook/react-native/pull/28650
Test Plan:
- Only execute code on Android P
- Added Android `BoxShadow` tests to RNTester app

Reviewed By: mdvacca
Differential Revision: D21125479
Pulled By: shergin
fbshipit-source-id: 14dcc023977d7a9d304fabcd3c90bcf34482f137
Summary:
Changes RNTester, first attempt in the direction of improving the RNTester overall. Related ticket: #24647
Changed the `js` directory of the RNTester to have the following structure:
```
- js
- assets
- components
- examples
- types
- utils
```
* **assets**
_Any images, gifs, and media content_
* **components**
_All shared components_
* **examples**
_Example View/Components to be rendered by the App_
* **types**
_Shared flow types_
* **utils**
_Shared utilities_
## Changelog
[General] [Changed] - Update folder structure of RNTester's JS directory.
Pull Request resolved: https://github.com/facebook/react-native/pull/25013
Differential Revision: D15515773
Pulled By: cpojer
fbshipit-source-id: 0e4b6386127f338dca0ffe8c237073be53a9e221