WIP: Add an explicit NDK version to RNTester and ReactAndroid (#29987)

Summary:
When I try to run RNTester with Gradle the RNTester Required me to use **NDK 20.0.5594570**. I can't seem to find an explicit NDK version anywhere in ReactAndroid and RNTester. This PR Aims to add an explicit NDK version to RNTester and ReactAndroid.

![Screenshot from 2020-09-19 21-13-17](https://user-images.githubusercontent.com/8868908/93669563-444fcf00-fabf-11ea-8822-93264c5bb736.png)

## Changelog
[Android] [Added] - Add an explicit NDK version to RNTester and ReactAndroid.

Pull Request resolved: https://github.com/facebook/react-native/pull/29987

Test Plan: Build manually from RNTester

Reviewed By: fkgozali

Differential Revision: D23911371

Pulled By: ShikaSD

fbshipit-source-id: 2f297c73890c0eb0bfec0e2ba7ec5755b4d84243

.circleci/config.yml

@@ -611,11 +611,11 @@ jobs:
         default: false
     environment:
       - ANDROID_HOME: "C:\\Android\\android-sdk"
-      - ANDROID_NDK: "C:\\Android\\android-sdk\\ndk\\19.2.5345600"
+      - ANDROID_NDK: "C:\\Android\\android-sdk\\ndk\\20.1.5948944"
       - ANDROID_BUILD_VERSION: 28
       - ANDROID_TOOLS_VERSION: 29.0.3
       - GRADLE_OPTS: -Dorg.gradle.daemon=false
-      - NDK_VERSION: 19.2.5345600
+      - NDK_VERSION: 20.1.5948944
     steps:
       - checkout
 

ReactAndroid/build.gradle

@@ -242,26 +242,28 @@ def getNdkBuildName() {
 }
 
 def findNdkBuildFullPath() {
+    // android.ndkDirectory should return project.android.ndkVersion ndkDirectory
+    def ndkDir = android.ndkDirectory ? android.ndkDirectory.absolutePath : null
+    if (ndkDir) {
+        return new File(ndkDir, getNdkBuildName()).getAbsolutePath()
+    }
+
     // we allow to provide full path to ndk-build tool
     if (hasProperty("ndk.command")) {
         return property("ndk.command")
     }
     // or just a path to the containing directory
     if (hasProperty("ndk.path")) {
-        def ndkDir = property("ndk.path")
+        ndkDir = property("ndk.path")
         return new File(ndkDir, getNdkBuildName()).getAbsolutePath()
     }
 
+    // @TODO ANDROID_NDK && ndk.dir is deprecated and will be removed in the future.
     if (System.getenv("ANDROID_NDK") != null) {
-        def ndkDir = System.getenv("ANDROID_NDK")
+        ndkDir = System.getenv("ANDROID_NDK")
         return new File(ndkDir, getNdkBuildName()).getAbsolutePath()
     }
 
-    def ndkDir = android.ndkDirectory ? android.ndkDirectory.absolutePath : null
-
-    if (ndkDir) {
-        return new File(ndkDir, getNdkBuildName()).getAbsolutePath()
-    }
     return null
 }
 
@@ -377,7 +379,7 @@ task extractJNIFiles {
 
 android {
     compileSdkVersion 29
-
+    ndkVersion ANDROID_NDK_VERSION
     compileOptions {
         sourceCompatibility(JavaVersion.VERSION_1_8)
         targetCompatibility(JavaVersion.VERSION_1_8)

build.gradle.kts

@@ -34,4 +34,9 @@ allprojects {
         google()
         jcenter()
     }
+
+    // used to override ndk path on CI
+    if (System.getenv("LOCAL_ANDROID_NDK_VERSION") != null) {
+      setProperty("ANDROID_NDK_VERSION", System.getenv("LOCAL_ANDROID_NDK_VERSION"))
+    }
 }

gradle.properties

@@ -3,3 +3,5 @@
 org.gradle.daemon=true
 org.gradle.jvmargs=-Xmx4g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
 org.gradle.parallel=true
+
+ANDROID_NDK_VERSION=20.1.5948944

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

@@ -127,7 +127,7 @@ def useIntlJsc = false
 
 android {
     compileSdkVersion 29
-
+    ndkVersion ANDROID_NDK_VERSION
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8