More flutter upgrades

flutter/android/app/build.gradle

@@ -3,7 +3,9 @@ plugins {
     // START: FlutterFire Configuration
     id 'com.google.gms.google-services'
     // END: FlutterFire Configuration
-    id "kotlin-android"
+    // Kotlin is provided by Flutter's built-in Kotlin support (the flutter-gradle-plugin
+    // auto-applies kotlin-android). KGP stays declared in settings.gradle so it remains
+    // on the classpath. See https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-app-developers
     id "dev.flutter.flutter-gradle-plugin"
 }
 
@@ -42,10 +44,6 @@ android {
         targetCompatibility JavaVersion.VERSION_17
     }
 
-    kotlinOptions {
-        jvmTarget = '17'
-    }
-
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }
@@ -75,6 +73,12 @@ android {
     }
 }
 
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17
+    }
+}
+
 flutter {
     source '../..'
 }

flutter/android/gradle.properties

@@ -1,3 +1,7 @@
 org.gradle.jvmargs=-Xmx4G
 android.useAndroidX=true
 android.enableJetifier=true
+# This builtInKotlin flag was added automatically by Flutter migrator
+android.builtInKotlin=false
+# This newDsl flag was added automatically by Flutter migrator
+android.newDsl=false