Android 4.1 + xposed 52: prevent clearApplicationUserData

import java.lang.reflect.Method;
 
import de.robv.android.xposed.IXposedHookCmdInit;
import de.robv.android.xposed.XC_MethodHook;
import de.robv.android.xposed.XposedBridge;
import de.robv.android.xposed.XposedHelpers;
import de.robv.android.xposed.callbacks.XC_LoadPackage;
 
public class Mypackage implements IXposedHookCmdInit
{
    @Override
    public void initCmdApp(StartupParam startupParam) throws Throwable {
        if (!startupParam.startClassName.equals("com.android.commands.pm.Pm")) {
            return;
        }
        //XposedBridge.log("startup:" + startupParam.startClassName);
 
        /*
         Final Fantasy 3 has a native library lib__57d5__.so that tries to clear the data
         for all apk files in /data/app/. We do not know why.
 
         It fails to do this for root-owned packages like this xposed module.
         See
         https://forum.xda-developers.com/xposed/framework-xposed-rom-modding-modifying-t1574401/page170#1700
 
         We simply prevent it from doing that.
 
         https://android.googlesource.com/platform/frameworks/base/+/refs/tags/android-4.1.2_r1/core/java/android/app/ActivityManagerNative.java#2880
 
         public boolean clearApplicationUserData(
             String packageName, IPackageDataObserver observer, final int userId
         )
         */
        XposedHelpers.findAndHookMethod(
            "android.app.ActivityManagerProxy",
            null,
            "clearApplicationUserData",
            String.class,
            "android.content.pm.IPackageDataObserver",
            int.class,
            new XC_MethodHook() {
                @Override
                protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
                    String packageName = (String) param.args[0];
                    XposedBridge.log("clearApplicationUserData: " + packageName);
                    if (!packageName.equals("mypackage")) {
                        return;
                    }
 
                    param.setResult(true);
 
                    //we do not have direct access to IPackageDataObserver, so we have to dance
                    Object observer = param.args[1];
                    if(observer != null) {
                        Class<?> iPackageDataObserverClass = Class.forName("android.content.pm.IPackageDataObserver");
                        Class<?>[] paramTypes = {String.class, boolean.class};
                        Method onRemoveCompletedMethod = iPackageDataObserverClass.getMethod("onRemoveCompleted", paramTypes);
                        Object[] params = {packageName, true};
                        try {
                            onRemoveCompletedMethod.invoke(observer, params);
                            //observer.onRemoveCompleted(packageName, true);
                        } catch (Exception e) {
                            XposedBridge.log("Observer no longer exists.");
                        }
                    }
                    //end dance
                }
            }
        );
 
    }
}