build.gradle: set Android SDK Build Tools version to 23.0.1 (#747)

`[email protected]` release introduces Android SDK Build Tools inconsistency between React Native app and react-native-code-push Module.
It's convenient to have the same version of Android SDK Build Tools both for React Native app and react-native-code-push module, due to facebook/react-native#11422 (comment)

Author: sergey-akhalkov

android/app/build.gradle

@@ -2,7 +2,7 @@ apply plugin: "com.android.library"
 
 android {
     compileSdkVersion 23
-    buildToolsVersion "23.0.3"
+    buildToolsVersion "23.0.1"
 
     defaultConfig {
         minSdkVersion 16