fix: ios launcher icon bug fix

leaderboard_app/android/app/build.gradle.kts

@@ -41,10 +41,13 @@ android {
 
     signingConfigs {
         create("release") {
-            keyAlias = keystoreProperties["keyAlias"] as String
-            keyPassword = keystoreProperties["keyPassword"] as String
-            storeFile = keystoreProperties["storeFile"]?.let { file(it) }
-            storePassword = keystoreProperties["storePassword"] as String
+            // Use getProperty to avoid a ClassCastException when key.properties is missing.
+            // If key.properties doesn't exist the properties will be null and getProperty will
+            // return null instead of throwing; values can be null for debug builds.
+            keyAlias = keystoreProperties.getProperty("keyAlias")
+            keyPassword = keystoreProperties.getProperty("keyPassword")
+            storeFile = keystoreProperties.getProperty("storeFile")?.let { file(it) }
+            storePassword = keystoreProperties.getProperty("storePassword")
         }
     }