Enable minification and resource shrinking

app/build.gradle

@@ -108,8 +108,8 @@ android {
             //applicationIdSuffix '.release'
             manifestPlaceholders.put("app_name", "@string/app_name")
 
-            minifyEnabled false
+            minifyEnabled true
-            shrinkResources false
+            shrinkResources true
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro', 'cronet-proguard-rules.pro'
         }
         debug {