我正在使用系统密钥签署我的应用程序，但无法获得系统权限

Question

我想使用系统密钥获取我的应用程序的系统权限。 我已使用 testkey.x509.pem 和 testkey.pk8 对该应用进行了签名 / build / target / product / security / （文件夹中没有其他键）但运行时检查显示我的应用程序不是系统应用程序。

要检查我使用以下代码

/**
 * Match signature of application to identify that if it is signed by system
 * or not.
 * 
 * @param packageName
 *            package of application. Can not be blank.
 * @return <code>true</code> if application is signed by system certificate,
 *         otherwise <code>false</code>
 */
public boolean isSystemApp(String packageName) {
    try {
        // Get packageinfo for target application
        PackageInfo targetPkgInfo = mPackageManager.getPackageInfo(
                packageName, PackageManager.GET_SIGNATURES);
        // Get packageinfo for system package
        PackageInfo sys = mPackageManager.getPackageInfo(
                "android", PackageManager.GET_SIGNATURES);
        // Match both packageinfo for there signatures
        return (targetPkgInfo != null && targetPkgInfo.signatures != null && sys.signatures[0]
                .equals(targetPkgInfo.signatures[0]));
    } catch (PackageManager.NameNotFoundException e) {
        return false;
    }
}

我做错了什么？