Enabled R8 build minification

app/build.gradle

@@ -29,12 +29,9 @@ android {
     }
     buildTypes {
         release {
-            postprocessing {
-                removeUnusedCode true
-                removeUnusedResources true
-                obfuscate false
-                optimizeCode true
-            }
+            minifyEnabled true
+            shrinkResources true
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
     buildFeatures {