Update add to app code to run on modern versions of agp and gradle. (#2330)

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add_to_app/plugin/android_using_plugin/app/build.gradle

@@ -3,11 +3,11 @@ apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 33
+    compileSdk 34
     defaultConfig {
         applicationId "dev.flutter.example.androidusingplugin"
-        minSdkVersion 19
-        targetSdkVersion 33
+        minSdkVersion 21
+        targetSdk 34
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -17,19 +17,29 @@ android {
             minifyEnabled false
         }
     }
+    // Remove when #flutter/flutter/issues/150955 is merged to stable.
+    lintOptions {
+        checkReleaseBuilds false
+    }
+    // Keep java and kotlin versions in sync.
     compileOptions {
         sourceCompatibility 1.8
         targetCompatibility 1.8
     }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
+
+    namespace 'dev.flutter.example.androidusingplugin'
 }
 
 dependencies {
     implementation project(':flutter')
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'androidx.appcompat:appcompat:1.6.1'
-    implementation 'androidx.core:core-ktx:1.10.1'
+    implementation 'androidx.appcompat:appcompat:1.7.0'
+    implementation 'androidx.core:core-ktx:1.13.1'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.2.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.6.1'
 }

add_to_app/plugin/android_using_plugin/app/src/main/AndroidManifest.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="dev.flutter.example.androidusingplugin">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <application
         android:name=".MyApplication"