expose IS_TESTING for Platform module

Summary: Introduced IS_TESTING flag on Platform module for android as well. This is useful for testing environment.

Reviewed By: mmmulani

Differential Revision: D4429662

fbshipit-source-id: 33711d7fb5666f0bac8aee444b71261f7f12770f

Author: fkgozali

Libraries/Utilities/Platform.android.js

@@ -18,6 +18,10 @@ const Platform = {
     const AndroidConstants = require('NativeModules').AndroidConstants;
     return AndroidConstants && AndroidConstants.Version;
   },
+  get isTesting(): boolean {
+    const constants = require('NativeModules').AndroidConstants;
+    return constants && constants.isTesting;
+  },
   select: (obj: Object) => obj.android,
 };
 

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoModule.java

@@ -25,6 +25,8 @@
 @ReactModule(name = "AndroidConstants")
 public class AndroidInfoModule extends BaseJavaModule {
 
+  private static final String IS_TESTING = "IS_TESTING";
+
   @Override
   public String getName() {
     return "AndroidConstants";
@@ -35,6 +37,7 @@ public String getName() {
     HashMap<String, Object> constants = new HashMap<>();
     constants.put("Version", Build.VERSION.SDK_INT);
     constants.put("ServerHost", AndroidInfoHelpers.getServerHost());
+    constants.put("isTesting", "true".equals(System.getProperty(IS_TESTING)));
     return constants;
   }
 }