prefer ShadowUserManager.addUserProfile(UserHandle) to ensure consistency of profiles known to the UserManager. Furthermore, calling this method for the current user, i.e: Process.myUserHandle() is no longer necessary as this user is always known to UserManager and has a preassigned serial number.
Do not depend on this method to override services as it will be removed in a future update. The preferered method is use the shadow of the corresponding service.