Yoast Meta Description not being picked up for og: title and twitter: title

@ahmedkaludi, this is similar to the ticket we resolved for the title not getting picked up (https://github.com/ahmedkaludi/accelerated-mobile-pages/issues/3207).

In order to fix this one, you will need to edit the function ampforwp_yoast_opengraph_description() in the file /plugins/accelerated-mobile-pages/templates/features.php. And add a fallback for

$desc = trim( WPSEO_Meta::get_value( 'twitter-description', $page_id ) );

and

$desc = trim( WPSEO_Meta::get_value( 'opengraph-description', $page_id ) );