Use node resolver to locate React Native package (#472)

Author: tomekzaw

android/build.gradle

@@ -52,21 +52,10 @@ def resolveReactNativeDirectory() {
     return file(reactNativeLocation)
   }
 
-  // monorepo workaround
-  // react-native can be hoisted or in project's own node_modules
-  def reactNativeFromProjectNodeModules = file("${rootProject.projectDir}/../node_modules/react-native")
-  if (reactNativeFromProjectNodeModules.exists()) {
-    return reactNativeFromProjectNodeModules
-  }
-
-  def reactNativeFromLiveMarkdownMonorepo = file("${projectDir}/../../../node_modules/react-native")
-  if (reactNativeFromLiveMarkdownMonorepo.exists()) {
-    return reactNativeFromLiveMarkdownMonorepo
-  }
-
-  def reactNativeFromNodeModulesWithLiveMarkdown = file("${projectDir}/../../react-native")
-  if (reactNativeFromNodeModulesWithLiveMarkdown.exists()) {
-    return reactNativeFromNodeModulesWithLiveMarkdown
+  // Fallback to node resolver for custom directory structures like monorepos.
+  def reactNativePackage = file(["node", "--print", "require.resolve('react-native/package.json')"].execute(null, rootDir).text.trim())
+  if (reactNativePackage.exists()) {
+    return reactNativePackage.parentFile
   }
 
   throw new GradleException("[react-native-live-markdown] Unable to resolve react-native location in node_modules. Your app should define `REACT_NATIVE_NODE_MODULES_DIR` extension property in `app/build.gradle` with a path to react-native in node_modules.")