Add condition of user capability in WP_query

#SOLVED#
Issue is solved by defining the meta_query conditions with an if statement. So if current_user_can(‘subscriber’) the meta_query includes the conditions, otherwise the query includes all posts.

This is the code in case this is helpful for anyone else:

<?php
//create variables
$paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1;
$current_user_id = get_current_user_id();
//check if current user is a subscriber and define meta_query arguments

$args = array(
    'post_type' => 'promotions',
    'posts_per_page' => 10,
    'meta_key'          => 'promo_start_date',
    'orderby'           => 'meta_value_num',
    'order'             => 'DESC',
    'paged' => $paged
);

if (current_user_can( 'subscriber' )) {
    // Add meta_query
    $args['meta_query'] = array(
        'relation'      => 'OR',
        array(
            'key'     => 'dedicated_promotion',
            'value'   => $current_user_id,
            'compare' => 'LIKE'
        ),
        array(
            'key'     => 'dedicated_promotion',
            'value'   => '',
            'compare' => '='
        )
      );
}

//set up the query
$query = new WP_Query($args);
if ( $query->have_posts() ) : ?>