Aperture: Enable minify/shrink/proguard

Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com>
Change-Id: Ib30c7e6fb3621308d6a7446b0a6075cfdb4c75cd
diff --git a/app/build.gradle b/app/build.gradle
index 29402c1..31ea115 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -18,8 +18,15 @@
 
     buildTypes {
         release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+            // Enables code shrinking, obfuscation, and optimization.
+            minifyEnabled true
+
+            // Enables resource shrinking.
+            shrinkResources true
+
+            // Includes the default ProGuard rules files.
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'),
+                    'proguard-rules.pro'
         }
     }
     compileOptions {