Use android-sdk-manager plugin to automate downloading Android SDK components.

build.gradle

@@ -1,10 +1,17 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
+task wrapper (type:Wrapper) {
+    gradleVersion = '2.2.1'
+    distributionUrl = 'https://services.gradle.org/distributions/gradle-2.2.1-all.zip'
+}
+
 buildscript {
     repositories {
         jcenter()
+        mavenCentral()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:1.0.0'
+        classpath 'com.jakewharton.sdkmanager:gradle-plugin:0.12.0'
     }
 }
 
@@ -13,3 +20,12 @@ allprojects {
         jcenter()
     }
 }
+
+subprojects {
+    def androidHome
+
+    if ((androidHome = System.env.'ANDROID_HOME')
+            && (androidHome = androidHome as File).exists()
+            && androidHome.canWrite())
+        apply plugin: 'android-sdk-manager'
+}