Fixed wrong usage of require when resolving supportsCodegenConfig

When resolving the version inside `react-native-config` which is used by the autolinking gradle tasks, the wrong use of require was used.

This fix changes from using `require.main.require` -> `require`.

The difference is that require.main.require resolves from the entry point (main script), while require resolves from the location of the current file.

Closes callstack#652

package/react-native.config.js

@@ -1,6 +1,6 @@
 let supportsCodegenConfig = false;
 try {
-  const rnCliAndroidVersion = require.main.require(
+  const rnCliAndroidVersion = require(
     '@react-native-community/cli-platform-android/package.json',
   ).version;
   const [major] = rnCliAndroidVersion.split('.');