升级到Android Studio海豚后|2021.3.1，应用程序未编译。它显示
针对Android 12及更高版本的应用需要在相应组件定义了Intent过滤器时为android:exported指定显式值
我已经用android：exported=“false”设置了所有的活动。但是它仍然显示这个问题。
我的清单文件：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.something">
 <application
    android:requestLegacyExternalStorage="true"
    android:label="something"
    android:icon="@mipmap/ic_launcher">
    <activity
        android:name=".MainActivity"
        android:exported="false"
        android:launchMode="singleTop"
        android:theme="@style/LaunchTheme"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize"
        >

        <meta-data
          android:name="io.flutter.embedding.android.NormalTheme"

          android:resource="@style/NormalTheme"
          />
       

        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
    <!-- Don't delete the meta-data below.
         This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
    <meta-data
        android:name="flutterEmbedding"
        android:value="2" />
</application>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

我的Gradle文件：

def localProperties = new Properties()
  def localPropertiesFile = rootProject.file('local.properties')
  if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
    localProperties.load(reader)
   }
}  

 def flutterRoot = localProperties.getProperty('flutter.sdk')
 if (flutterRoot == null) {
    throw  GradleException("Flutter SDK not found. Define location with flutter.sdk in 
 the local.properties file.")
 }

 def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
 if (flutterVersionCode == null) {
   flutterVersionCode = '11'
 }

 def flutterVersionName = localProperties.getProperty('flutter.versionName')
  if (flutterVersionName == null) {
   flutterVersionName = '11.0'
  }

 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 apply plugin: 'com.android.application'
 apply plugin: 'com.google.gms.google-services'
 def keystoreProperties = new Properties()
def keystorePropertiesFile = rootProject.file('key.properties')
 if (keystorePropertiesFile.exists()) {
 keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
}

 android {

    compileSdkVersion 33

    sourceSets {
     main.java.srcDirs += 'src/main/kotlin'
    }

   defaultConfig {
    // TODO: Specify your own unique Application ID 
    (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.something.something1.com"
    minSdkVersion 21
    targetSdkVersion 33
    multiDexEnabled true
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
   }
   signingConfigs {
    release {
        keyAlias keystoreProperties['keyAlias']
        keyPassword keystoreProperties['keyPassword']
        storeFile keystoreProperties['storeFile'] ? 
    file(keystoreProperties['storeFile']) : null
        storePassword keystoreProperties['storePassword']
    }
   }
   buildTypes {
       release {
        signingConfig signingConfigs.release
       }
   }

 }

   flutter {
     source '../..'
}

   dependencies {
    implementation platform('com.google.firebase:firebase-bom:28.2.1')
    implementation 'com.google.firebase:firebase-analytics'
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
}