Hello Diego,
Thanks in advance for your question.
For iOS Devices this is Icon is not displayed. iOS have a different way to provide this feedback to the user by adding a blue bar on the phone tray
For Android Devices is not possible to hide the Icon on the phone Tray.
The Icon is displayed to indicate the user that the phone is being tracked. Android requires this type of information being provided to the users when such is happening.
You can change the Icon to different one without changing the App icon, but you can't hide it.
Best Regards,
Bruno Domingues