AAPT: error: attribute android:preserveLegacyExternalStorage not found

Question

I am migrating an app to API level 30 and trying to follow the guidelines from here. It says:

If your app targets Android 11

Set the preserveLegacyExternalStorage flag to true to preserve the legacy storage model so that your app can migrate a user's data when they upgrade to the new version of your app that targets Android 11.

As advised, I am setting the flag in respective build flavor's manifest file and there are no warnings or errors inside the code editor. However, problems occur when I try to build the app. I am receiving the following error:

AndroidManifest.xml:25: AAPT: error: attribute android:preserveLegacyExternalStorage not found.

AndroidManifest.xml is the following:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <application android:preserveLegacyExternalStorage="true">
    </application>
</manifest>

The relevant parts from build.gradle file are the following:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.2"

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        applicationId "com.example.test"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 41
        versionName "5.3.0"
    }

    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-project.txt'
        }
    }

    flavorDimensions "payments", "API"
    productFlavors {
        google {
            dimension "payments"
        }
        cc {
            dimension "payments"
        }
        defaultAPI {
            minSdkVersion 30
            targetSdkVersion 30
            dimension "API"
        }
        maxAPI29 {
            dimension "API"
            targetSdkVersion 29
            versionNameSuffix "-maxAPI29"
        }
    }
}

dependencies {
    ...
}

That is, build tools and compile SDK version are set to 30. What else I might be missing?