Adds proguard config.

app/build.gradle

@@ -44,16 +44,16 @@ android {
         release {
             // Enables code shrinking, obfuscation, and optimization for only
             // your project's release build type.
-//            minifyEnabled true
+            minifyEnabled true
 
             // Enables resource shrinking, which is performed by the
             // Android Gradle plugin.
-//            shrinkResources true
+            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'
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
     compileOptions {