Code review comment: It might be better to be use a StringBuilder here, but it's not terribly important

Code under review:
private void detectAndLogSpecificSpringPropertiesIfExist() {
        Config config = ConfigProvider.getConfig();

        Iterable<String> iterablePropertyNames = config.getPropertyNames();
        List<String> propertyNames = new ArrayList<String>();
        iterablePropertyNames.forEach(propertyNames::add);
        List<String> springProperties = propertyNames.stream().filter(s -> pattern.matcher(s).matches()).collect(toList());
        String notSupportedProperties = "";

        if (!springProperties.isEmpty()) {
            for (String sp : springProperties) {
                switch (sp) {
                    case SPRING_JPA_SHOW_SQL:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_SHOW_SQL
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_LOG_SQL + "\n";
                        break;
                    case SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_DIALECT + "\n";
                        break;
                    case SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT_STORAGE_ENGINE:
                        notSupportedProperties = notSupportedProperties + "\t- "
                                + SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT_STORAGE_ENGINE + " should be replaced by "
                                + QUARKUS_HIBERNATE_ORM_DIALECT_STORAGE_ENGINE + "\n";
                        break;
                    case SPRING_JPA_GENERATE_DDL:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_GENERATE_DDL
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_DATABASE_GENERATION + "\n";
                        break;
                    default:
                        notSupportedProperties = notSupportedProperties + "\t- " + sp + "\n";
                        break;
                }
            }
            LOGGER.warnf(
                    "Quarkus does not support the following Spring Boot configuration properties: %n%s",
                    notSupportedProperties);
        }
    }

Line commented on: String notSupportedProperties = "";

Revised code:
private void detectAndLogSpecificSpringPropertiesIfExist() {
        Config config = ConfigProvider.getConfig();

        Iterable<String> iterablePropertyNames = config.getPropertyNames();
        List<String> propertyNames = new ArrayList<String>();
        iterablePropertyNames.forEach(propertyNames::add);
        List<String> springProperties = propertyNames.stream().filter(s -> pattern.matcher(s).matches()).collect(toList());
        String notSupportedProperties = "";

        if (!springProperties.isEmpty()) {
            for (String sp : springProperties) {
                switch (sp) {
                    case SPRING_JPA_SHOW_SQL:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_SHOW_SQL
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_LOG_SQL + "\n";
                        break;
                    case SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_DIALECT + "\n";
                        break;
                    case SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT_STORAGE_ENGINE:
                        notSupportedProperties = notSupportedProperties + "\t- "
                                + SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT_STORAGE_ENGINE + " should be replaced by "
                                + QUARKUS_HIBERNATE_ORM_DIALECT_STORAGE_ENGINE + "\n";
                        break;
                    case SPRING_JPA_GENERATE_DDL:
                        notSupportedProperties = notSupportedProperties + "\t- " + SPRING_JPA_GENERATE_DDL
                                + " should be replaced by " + QUARKUS_HIBERNATE_ORM_DATABASE_GENERATION + "\n";
                        break;
                    default:
                        notSupportedProperties = notSupportedProperties + "\t- " + sp + "\n";
                        break;
                }
            }
            LOGGER.warnf(
                    "Quarkus does not support the following Spring Boot configuration properties: %n%s",
                    notSupportedProperties);
        }
    }