Release mode: add some codeoptimization to look how it behaves

app/build.gradle.kts

@@ -49,13 +49,13 @@ android {
         named("release") {
             resValue("string", "app_name", "ElementX")
             signingConfig = signingConfigs.getByName("debug")
-            isMinifyEnabled = false
-            setProguardFiles(
-                listOf(
-                    getDefaultProguardFile("proguard-android-optimize.txt"),
-                    "proguard-rules.pro"
-                )
-            )
+
+            postprocessing {
+                isRemoveUnusedCode = true
+                isObfuscate = false
+                isOptimizeCode = true
+                proguardFiles("proguard-rules.pro")
+            }
         }
 
         register("nightly") {

app/proguard-rules.pro

@@ -0,0 +1,26 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.kts.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# JNA
+-keep class com.sun.jna.** { *; }
+-keep class * implements com.sun.jna.** { *; }
+
+# kotlinx.serialization
+
+# Kotlin serialization looks up the generated serializer classes through a function on companion
+# objects. The companions are looked up reflectively so we need to explicitly keep these functions.
+-keepclasseswithmembers class **.*$Companion {
+    kotlinx.serialization.KSerializer serializer(...);
+}
+# If a companion has the serializer function, keep the companion field on the original type so that
+# the reflective lookup succeeds.
+-if class **.*$Companion {
+  kotlinx.serialization.KSerializer serializer(...);
+}
+-keepclassmembers class <1>.<2> {
+  <1>.<2>$Companion Companion;
+}