android: setup app signing

android/app/build.gradle.kts

@@ -1,3 +1,6 @@
+import java.util.Properties
+import java.io.FileInputStream
+
 plugins {
     id("com.android.application")
     id("kotlin-android")
@@ -5,6 +8,12 @@ plugins {
     id("dev.flutter.flutter-gradle-plugin")
 }
 
+val keystoreProperties = Properties()
+val keystorePropertiesFile = rootProject.file("key.properties")
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
+}
+
 android {
     namespace = "com.example.sheetless"
     compileSdk = flutter.compileSdkVersion
@@ -30,11 +39,18 @@ android {
         versionName = flutter.versionName
     }
 
+    signingConfigs {
+        create("release") {
+            keyAlias = keystoreProperties["keyAlias"] as String
+            keyPassword = keystoreProperties["keyPassword"] as String
+            storeFile = keystoreProperties["storeFile"]?.let { file(it) }
+            storePassword = keystoreProperties["storePassword"] as String
+        }
+    }
+
     buildTypes {
         release {
-            // TODO: Add your own signing config for the release build.
+            signingConfig = signingConfigs.getByName("release")
-            // Signing with the debug keys for now, so `flutter run --release` works.
-            signingConfig = signingConfigs.getByName("debug")
         }
     }
 }