new: integrate Google Services for app distribution

androidApp/build.gradle.kts

@@ -4,6 +4,14 @@ plugins {
     alias(libs.plugins.androidApplication)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
+    // Used for App Distribution
+    alias(libs.plugins.googleServices) apply false
+}
+
+// Apply Google Services only when the Firebase config is present: google-services.json is not
+// tracked in git (see google-services.example.json), so builds must work without it.
+if (file("google-services.json").exists()) {
+    apply(plugin = libs.plugins.googleServices.get().pluginId)
 }
 
 kotlin {