Handle setAllowedCarriers() with empty list of carriers

        if (carriers == null || !SubscriptionManager.isValidPhoneId(slotIndex)) {

            return -1;

        }

        // Execute the method setCarrierRestrictionRules with an empty excluded list and

        // indicating priority for the allowed list.

        // Execute the method setCarrierRestrictionRules with an empty excluded list.

        // If the allowed list is empty, it means that all carriers are allowed (default allowed),

        // otherwise it means that only specified carriers are allowed (default not allowed).

        CarrierRestrictionRules carrierRestrictionRules = CarrierRestrictionRules.newBuilder()

                .setAllowedCarriers(carriers)

                .setDefaultCarrierRestriction(

                    CarrierRestrictionRules.CARRIER_RESTRICTION_DEFAULT_NOT_ALLOWED)

                    carriers.isEmpty()

                        ? CarrierRestrictionRules.CARRIER_RESTRICTION_DEFAULT_ALLOWED

                        : CarrierRestrictionRules.CARRIER_RESTRICTION_DEFAULT_NOT_ALLOWED)

                .build();

        int result = setCarrierRestrictionRules(carrierRestrictionRules);