point react gradle config to monorepo (#44901)

Summary:
Pull Request resolved: #44901

Point Gradle to the monorepo instead of a node_modules, as well as remove some commented out entries we're not interested in.

Changelog: [Internal]

Reviewed By: cortinico

Differential Revision: D58287786

packages/helloworld/android/app/build.gradle

@@ -9,36 +9,20 @@ apply plugin: "com.android.application"
 apply plugin: "org.jetbrains.kotlin.android"
 apply plugin: "com.facebook.react"
 
-/**
- * This is the configuration block to customize your React Native Android app.
- * By default you don't need to apply any configuration, just uncomment the lines you need.
- */
+def generatedConfig = file("../../.react-native.config").getText().replaceAll("HELLOWORLD_PATH", project.file("../../").absolutePath)
+
 react {
     /* Folders */
-    //   The root of your project, i.e. where "package.json" lives. Default is '..'
-    // root = file("../")
-    //   The folder where the react-native NPM package is. Default is ../node_modules/react-native
-    // reactNativeDir = file("../node_modules/react-native")
-    //   The folder where the react-native Codegen package is. Default is ../node_modules/@react-native/codegen
-    // codegenDir = file("../node_modules/@react-native/codegen")
-    //   The cli.js file which is the React Native CLI entrypoint. Default is ../node_modules/react-native/cli.js
-    // cliFile = file("../node_modules/react-native/cli.js")
-
-    /* Variants */
-    //   The list of variants to that are debuggable. For those we're going to
-    //   skip the bundling of the JS bundle and the assets. By default is just 'debug'.
-    //   If you add flavors like lite, prod, etc. you'll have to list your debuggableVariants.
-    // debuggableVariants = ["liteDebug", "prodDebug"]
-
-    /* Bundling */
-    //   A list containing the node command and its flags. Default is just 'node'.
-    // nodeExecutableAndArgs = ["node"]
-    //
-    //   The command to run when bundling. By default is 'bundle'
-    // bundleCommand = "ram-bundle"
-    //
-    //   The path to the CLI configuration file. Default is empty.
-    // bundleConfig = file(../rn-cli.config.js)
+    root = file("../")
+    reactNativeDir = file("../../../react-native")
+    codegenDir = file("../../../react-native-codegen")
+    // Our simplified bundle wrapper.
+    cliFile = file("../../scripts/bundle.js")
+    bundleCommand = ""
+    extraPackagerArgs = [
+        "--load-config",
+        generatedConfig
+    ]
     //
     //   The name of the generated asset file containing your JS bundle
     // bundleAssetName = "MyApplication.android.bundle"