ef-allow-contributors-edit-notifications.php

<?php
/**
 * Plugin Name: Edit Flow - Allow Contributors to edit Notifications
 */

function ef_allow_contributors_to_manage_notifications() {
		global $wp_roles;
		
		$role = 'contributor';
		$cap = 'edit_post_subscriptions';

		if ( $wp_roles->is_role( $role ) ) {
			$role = get_role( $role );
			$role->add_cap( $cap );
		}
}

add_action( 'admin_init', 'ef_allow_contributors_to_manage_notifications' );