RNGP - Remove unused applyAppPlugin

Summary:
This is part of a series of tasks to make the React Native Gradle Plugin (RNGP) variant-aware.

Here I'm removing the `applyAppPlugin` property which was never used. The new logic will apply the App Plugin if the `com.android.application` plugin is found.

I've also removed the corresponding tests. New one will follow afterwards

Changelog:
[Internal] [Changed] - RNGP - Remove unused applyAppPlugin

Reviewed By: cipolleschi

Differential Revision: D40547689

fbshipit-source-id: ce1089498a586a43cb5e07950767c2c4b51b4597

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactExtension.kt

@@ -22,12 +22,6 @@ abstract class ReactExtension @Inject constructor(project: Project) {
 
   private val objects = project.objects
 
-  /**
-   * Whether the React App plugin should apply its logic or not. Set it to false if you're still
-   * relying on `react.gradle` to configure your build. Default: false
-   */
-  val applyAppPlugin: Property<Boolean> = objects.property(Boolean::class.java).convention(false)
-
   /**
    * The path to the root of your project. This is the path to where the `package.json` lives. All
    * the CLI commands will be invoked from this folder as working directory.

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt

@@ -40,26 +40,26 @@ class ReactPlugin : Plugin<Project> {
     if ((jvmVersion?.toIntOrNull() ?: 0) <= 8) {
       project.logger.error(
           """
-      
+
       ********************************************************************************
-      
+
       ERROR: requires JDK11 or higher.
       Incompatible major version detected: '$jvmVersion'
-      
+
       ********************************************************************************
-      
+
       """
               .trimIndent())
       exitProcess(1)
     }
   }
 
   private fun applyAppPlugin(project: Project, config: ReactExtension) {
-    configureReactNativeNdk(project, config)
-    configureBuildConfigFields(project)
-    configureDevPorts(project)
-    project.afterEvaluate {
-      if (config.applyAppPlugin.getOrElse(false)) {
+    project.pluginManager.withPlugin("com.android.application") {
+      configureReactNativeNdk(project, config)
+      configureBuildConfigFields(project)
+      configureDevPorts(project)
+      project.afterEvaluate {
         val isAndroidLibrary = project.plugins.hasPlugin("com.android.library")
         val variants =
             if (isAndroidLibrary) {

packages/rn-tester/android/app/build.gradle

@@ -76,7 +76,6 @@ plugins {
  */
 
 react {
-    applyAppPlugin = true
     cliPath = "../../../../cli.js"
     bundleAssetName = "RNTesterApp.android.bundle"
     entryFile = file("../../js/RNTesterApp.android.js")