怎么在AndroidManifest的Application中使

<application
        android:name=".App"
        android:allowBackup="true"
        android:icon="${appicon}"
        android:label="${applabel}"
        android:roundIcon="${appicon}"
        android:supportsRtl="true"
        android:theme="@style/MainAppTheme"
        android:networkSecurityConfig="@xml/network_security_config"
        tools:replace="android:label,android:allowBackup">