Change Gravity Forms submit input to a button element

gravity-forms-button.php

<?php

function form_submit_button ($button, $form) {
	$button = str_replace("input", "button", $button);
	$button = str_replace("/", "", $button);
	$button .= "{$form['button']['text']}</button>";
	return $button;
}
add_filter('gform_submit_button', 'form_submit_button', 10, 5);

// It's not perfect - it leaves some inapplicable attributes in the element
// It leaves the important onclick and tab index intact