Adding permission to export file & falling back to working version of Gradle

tests/react-test-app/android/app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
     package="io.realm.react.testapp">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission. WRITE_EXTERNAL_STORAGE" />
 
     <application
       android:name=".MainApplication"

tests/react-test-app/android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.3.1'
+        classpath 'com.android.tools.build:gradle:1.2.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files