chore: update Jest preset to align with Jest 24 (#24062)

Summary:
Jest 24 includes [`testMatch` and `moduleFileExtensions`](https://github.com/facebook/jest/blob/c5fd7aae93764c13c259ae9a73846c10e84ae2a3/packages/jest-config/src/Defaults.ts#L70) that align with the ones that are currently there on master, because it added default handling for TypeScript as well. I think it's time for us to move to Jest 24. Is there a way we can tell users to upgrade Jest to certain version?

Fixes facebook/react-native#24060

[General] [Changed] - update Jest preset to align with Jest 24
Pull Request resolved: facebook/react-native#24062

Differential Revision: D14538988

Pulled By: cpojer

fbshipit-source-id: d8d152b8e8517b34144970f1cc1ed0b49f8b4e54

jest-preset.js

@@ -18,7 +18,6 @@ module.exports = {
     hasteImplModulePath: require.resolve('./jest/hasteImpl.js'),
     providesModuleNodeModules: ['react-native'],
   },
-  moduleFileExtensions: ['js', 'json', 'jsx', 'node', 'ts', 'tsx'],
   moduleNameMapper: {
     '^React$': require.resolve('react'),
   },
@@ -32,10 +31,6 @@ module.exports = {
   transformIgnorePatterns: [
     'node_modules/(?!(jest-)?react-native|react-clone-referenced-element)',
   ],
-  testMatch: [
-    '**/__tests__/**/*.(js|ts|tsx)',
-    '**/?(*.)+(spec|test).(js|ts|tsx)',
-  ],
   setupFiles: [require.resolve('./jest/setup.js')],
   testEnvironment: 'node',
 };