java.lang.SecurityException: Neither user 10032 nor current process has android.permission.MODIFY_PHONE_STATE

I'm working on a service to auto PIN/PUK when starting device. Service is launched at Boot time. I'm using ITelephony with reflexive methods. My phone is lollipop 5.1.1, it's a rooted nexus 5. My manifest has Android Studio says "Permission is only granted to system apps"

I'm using this code snippet :

    TelephonyManager tm = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);
        int state = tm.getSimState();

        if(state == TelephonyManager.SIM_STATE_PIN_REQUIRED || state == TelephonyManager.SIM_STATE_PUK_REQUIRED)
        {
            Log.d(TAG,"PIN PUK STATE = " + state );


            if (state  == TelephonyManager.SIM_STATE_PIN_REQUIRED ){
                try {
                    message += ", PIN Code required" ;
                    Class clazz = Class.forName(tm.getClass().getName());
                    if (clazz != null) {
                        Method m = clazz.getDeclaredMethod("getITelephony");
                        m.setAccessible(true);
                        Object iTelephony = m.invoke(tm);

                        Class params[] = new Class[1];
                        params[0] = String.class;

                        Method m2 = iTelephony.getClass().getDeclaredMethod("supplyPin", params);
                        m2.setAccessible(true);

                        Object i = m2.invoke(iTelephony, "1111");

                        Log.d(TAG, m2.toString() + " *** " + i.toString());
                    }
                }catch (Exception e) {
                    Log.d(TAG,"Impossible to unlock " + e.toString());
                    e.printStackTrace();

                }
            }

And I get this log :

07-20 10:31:33.109    1267-1267/eu.cabrera.pinunlocker W/System.err﹕ Caused by: java.lang.SecurityException: Neither user 10032 nor current process has android.permission.MODIFY_PHONE_STATE.
07-20 10:31:33.112    1267-1267/eu.cabrera.pinunlocker W/System.err﹕ at android.os.Parcel.readException(Parcel.java:1546)
07-20 10:31:33.112    1267-1267/eu.cabrera.pinunlocker W/System.err﹕ at android.os.Parcel.readException(Parcel.java:1499)
07-20 10:31:33.112    1267-1267/eu.cabrera.pinunlocker W/System.err﹕ at com.android.internal.telephony.ITelephony$Stub$Proxy.supplyPin(ITelephony.java:1540)

I've tested with a regular app and now with a system app, same problem.

Am I doing something bad? Is my app really system? I have copied eu.cabrera.pinunlocker.apk to /system/app

What do I need to grant my app the android.permission.MODIFY_PHONE_STATE?

Thanks for your help. Antoine

Did you try to put your app to /system/priv-app? Becouse if you need to grant system permission /system/priv-app is the correct location for your app. Only apks in /system/priv-app can use "system"-level permissions