ChangePasswordFormType.php

<?php
// ...
public function buildForm(FormBuilderInterface $builder, array $options)
    {
        parent::buildForm($builder, $options);

        $builder->add(
            'email',
            'email',
            array(
                'label' => 'Email',
                'constraints' => new Email(),
            )
        );

        $builder->add(
            'termsandconditions',
            'checkbox',
            array(
                'label' => 'sso.terms-and-conditions',
                'constraints' => new NotNull(),
                'mapped' => false
            )
        );
    }