Set system app as lock task package using device owner

Question

My app is a system signed Device-owner app, and i would like to set my own app in lock task mode.

However the method in DevicePolicyManager setLockTaskPackages doesn't work for system apps even if its the same app calling.

 if(BuildConfig.DEFAULT_OWNERSHIP.equals(Constants.OWNERSHIP_DEVICE_OWNER)) {
            devicePolicyManager.setLockTaskPackages(componentName, new String[]{context.getPackageName()});            
            startLockTask();
        }

I am looking for a work around for the same in which i am able to set my same app in lock task mode which is system signed