Java 7-ness

sample_app/build.gradle

@@ -1,17 +1,22 @@
 apply plugin: 'com.android.application'
 
-def versionMajor = 0
-def versionMinor = 0
-def versionPatch = 3
-def androidVersionCode = 3
+final def versionMajor = 0
+final def versionMinor = 0
+final def versionPatch = 3
+final def androidVersionCode = 3
 
-def targetSdk = rootProject.targetSdkVersion;
-def minSdkRed = rootProject.minSdkVersion;
+final def targetSdk = rootProject.targetSdkVersion;
+final def minSdkRed = rootProject.minSdkVersion;
 
 android {
     compileSdkVersion rootProject.compileSdkVersion
     buildToolsVersion rootProject.buildToolsVersion
 
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
+
     defaultConfig {
         minSdkVersion minSdkRed
         targetSdkVersion targetSdk