Controlling the visibility of a Freemius added admin notice

freemius-admin-notice-filter.php

<?php
    /**
     * @param bool  $show
     * @param array $msg {
     *     @var string $message The actual message.
     *     @var string $title An optional message title.
     *     @var string $type The type of the message ('success', 'update', 'warning', 'promotion').
     *     @var string $id The unique identifier of the message.
     *     @var string $manager_id The unique identifier of the notices manager. For plugins it would be the plugin's slug, for themes - `<slug>-theme`.
     *     @var string $plugin The product's title.
     *     @var string $wp_user_id An optional WP user ID that this admin notice is for.
     * }
     * @return bool
     */
    function my_custom_show_admin_notice( $show, $msg ) {
        if ('trial_promotion' == $msg['id']) {
            // Don't show the trial promotional admin notice. 
            return false;
        }

        return $show;
    }

    my_fs()->add_filter( 'show_admin_notice', 'my_custom_show_admin_notice', 10, 2 );