Enables obfuscation and minification for release builds.

app/build.gradle

@@ -26,7 +26,17 @@ android {
 
     buildTypes {
         release {
-            minifyEnabled false
+            // Enables code shrinking, obfuscation, and optimization for only
+            // your project's release build type.
+            minifyEnabled true
+
+            // Enables resource shrinking, which is performed by the
+            // Android Gradle plugin.
+            shrinkResources true
+
+            // Includes the default ProGuard rules files that are packaged with
+            // the Android Gradle plugin. To learn more, go to the section about
+            // R8 configuration files.
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }