add InitializeCore in getModulesRunBeforeMainModule (#38207)

Summary:
the `IntializeCore` is critical to react-native for setup polyfills. without this, we would have some erros like undefined `global.performance`. since the effort is now proposing `react-native/metro-config` as universal metro-config, it is better to have the `IntializeCore` in it.

we ran into issues when using expo-cli in bare react-native projects. it happens when using [the default metro config](https://github.com/facebook/react-native/blob/5f84d7338f42fe9b1d5bf2a9b1c8321b59551f15/packages/react-native/template/metro.config.js) and starting metro server without the react-native-community-cli.

### Why the issue does not happen on `yarn react-native start`?

when using `yarn react-native start`, the react-native-community-cli will merge its internal metro-config with the `InitializeCore` ([#1, [#2). that's why the issue doesn't happen on react-native-community-cli.

## Changelog:

[GENERAL][FIXED] - `global.performance` in undefined when starting metro from Expo CLI

Pull Request resolved: #38207

Test Plan:
```sh
$ npx react-native init RN072 --version 0.72
$ cd RN072
$ yarn add expo
$ npx expo run:ios
# then it hits the exception because the global.performance is undefined.
```

Reviewed By: rshest

Differential Revision: D47257439

Pulled By: huntie

fbshipit-source-id: ae294e684047e503d674f0c72563b56d1803ba36

packages/metro-config/index.js

@@ -49,6 +49,10 @@ function getDefaultConfig(
       unstable_conditionNames: ['require', 'import', 'react-native'],
     },
     serializer: {
+      // Note: This option is overridden in cli-plugin-metro (getOverrideConfig)
+      getModulesRunBeforeMainModule: () => [
+        require.resolve('react-native/Libraries/Core/InitializeCore'),
+      ],
       getPolyfills: () => require('@react-native/js-polyfills')(),
     },
     server: {