minor #18663 [Form] Fix tests added in #18180 (HeahDude)

This PR was submitted for the master branch but it was merged into the 3.0 branch instead (closes #18663).

Discussion
----------

[Form] Fix tests added in #18180

| Q             | A
| ------------- | ---
| Branch?       | 3.0+
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ~
| License       | MIT
| Doc PR        | ~

Commits
-------

c45a435 [Form] Fix tests added in #18180

src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php

@@ -153,7 +153,6 @@ public function testExpandedChoiceListWithBooleanAndNullValues()
     {
         $view = $this->factory->create('Symfony\Component\Form\Extension\Core\Type\ChoiceType', null, array(
             'choices' => $this->booleanChoicesWithNull,
-            'choices_as_values' => true,
             'expanded' => true,
         ))->createView();
 
@@ -179,7 +178,6 @@ public function testExpandedChoiceListWithBooleanAndNullValuesAndFalseAsPreSetDa
     {
         $view = $this->factory->create('Symfony\Component\Form\Extension\Core\Type\ChoiceType', false, array(
             'choices' => $this->booleanChoicesWithNull,
-            'choices_as_values' => true,
             'expanded' => true,
         ))->createView();