Jetpack::is_module PHP Method

    public static function is_module($module)
    {
        return !empty($module) && !validate_file($module, Jetpack::get_available_modules());
    }

function wpcf7_jetpack_admin_notices()
{
    global $wpdb;
    if (!class_exists('Jetpack') || !Jetpack::is_module('contact-form') || !in_array('contact-form', Jetpack::get_active_modules())) {
        return;
    }
    $q = "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_old_cf7_unit_id'";
    if (!$wpdb->get_var($q)) {
        return;
    }
    $desc_link = wpcf7_link(__('http://contactform7.com/jetpack-overrides-contact-forms/', 'contact-form-7'), __('Jetpack Overrides Contact Forms', 'contact-form-7'));
    ?>
<div class="notice notice-warning">
<p><?php 
    echo sprintf(esc_html(__('Jetpack may cause problems for other plugins in certain cases. For more details, see %s.', 'contact-form-7')), $desc_link);
    ?>
</p>
</div>
<?php 
}