Duplicate submit button on ajax form

Problem/Motivation

A single submit button on ajax form renders twice. Button appears in the
(at the bottom) and again in the

Steps to reproduce

Create a standard FormBase class and enable ajax for the submit.

$form['actions'] = ['#type' => 'actions'];

$form['actions']['send'] = [
'#type' => 'submit',
'#value' => $this->t('Email Denied Message'),
'#ajax' => [
'callback' => [$this, 'submitModalFormAjax'],
'event' => 'click',
],
];

return $form;

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes