Using the Android 12 knownSigner protection level flag

so I basically want to explicitly give another app the permission to access my broadcast receiver via the signature|knownSigner protection level.

I am running Android 12.0 (S) API 31 using Android SDK Build-Tools 33-rc4 with the following android attribute in my build.gradle:

android {
    compileSdk 31

    defaultConfig {
        applicationId "com.example.app"
        minSdk 31
        targetSdk 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

According to these sources

• https://developer.android.com/guide/topics/manifest/permission-element
• https://developer.android.com/reference/android/R.attr#protectionLevel
• https://developer.android.com/reference/android/R.attr#knownCerts
• https://developer.android.com/about/versions/12/features#safer-grant-signature-perms

I defined the permission in my apps AndroidManifest.xml as

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app">

    <permission android:name="com.example.app.permission.MY_PERMISSION"
        android:protectionLevel="signature|knownSigner"
        android:knownCerts="3a71b28418ed0ad6280d3e6639d29dcd654a42e441e60585607391ccdf1f25c8"/>

...

</manifest>

Now when trying to build the app, the validation for the AndroidManiest.xml fails with:

Invalid value for attribute permission#com.example.app.permission.MY_PERMISSION@protectionLevel at AndroidManifest.xml:6:9-56, value=(signature|knownSigner), acceptable delimiter-separated values are (normal|dangerous|signature|signatureOrSystem|privileged|system|development|appop|pre23|installer|verifier|preinstalled|setup|ephemeral|instant|runtime|oem|vendorPrivileged|textClassifier|wellbeing|documenter|configurator|incidentReportApprover|appPredictor|companion|retailDemo)

So I am wondering how to properly implement the knownSigner protection level flag. Can somebody help?

Thanks!