You could register your script in functions.php and then enqueue it right where you need. So, just as a mere example:
in functions.php
wp_register_script( 'gmaps','https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false', array(), '1.0', true );
and then in your layout code:
elseif( get_row_layout() == 'map' ):
$google_maps = get_sub_field('google_maps');
if( !empty($google_maps) ):
wp_enqueue_script('gmaps');
This will load google’s .js in footer just when you need it.
