update gradle and remove weird entry point (#2330)

index.android.js

-require('./playground/index');

index.ios.js

-require('./playground/index');

lib/android/app/build.gradle

 
 android {
     compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    buildToolsVersion "27.0.1"
 
     defaultConfig {
         minSdkVersion 16

lib/android/build.gradle

 
 buildscript {
     repositories {
+        mavenLocal()
+        mavenCentral()
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.0'
+        classpath 'com.android.tools.build:gradle:3.0.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
 allprojects {
     repositories {
         mavenLocal()
+        mavenCentral()
+        google()
         jcenter()
         maven {
             // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm

lib/android/gradle.properties

 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+
+# Disable incremental resource processing as it broke relase build
+# https://github.com/react-community/react-navigation/issues/1976
+# https://developer.android.com/studio/build/gradle-plugin-3-0-0.html
+android.enableAapt2=false

playground/android/app/build.gradle

 
 android {
     compileSdkVersion 25
-    buildToolsVersion "25.0.3"
+    buildToolsVersion "27.0.1"
 
     defaultConfig {
         applicationId "com.reactnativenavigation.playground"

playground/android/build.gradle

 
 buildscript {
     repositories {
-        jcenter()
+        mavenLocal()
+        mavenCentral()
         google()
+        jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.0.1'
 
 allprojects {
     repositories {
-        jcenter()
-        google()
         mavenLocal()
         mavenCentral()
+        google()
+        jcenter()
         maven {
             // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
             url "$rootDir/../../node_modules/react-native/android"

playground/android/gradle.properties

 # org.gradle.parallel=true
 
 android.useDeprecatedNdk=false
+# Disable incremental resource processing as it broke relase build
+# https://github.com/react-community/react-navigation/issues/1976
+# https://developer.android.com/studio/build/gradle-plugin-3-0-0.html
+android.enableAapt2=false

playground/android/gradle/wrapper/gradle-wrapper.properties

 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.3.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-bin.zip

scripts/start.js

   exec.killPort(8081);
   exec.execSync(`watchman watch-del-all || true`);
   exec.execSync(`adb reverse tcp:8081 tcp:8081 || true`);
-  exec.execSync(`node ./node_modules/react-native/local-cli/cli.js start`);
+  exec.execSync(`node ./node_modules/react-native/local-cli/cli.js start --root ./playground/`);
 }