Default 'use_featured_hero_image' value is incorrect

[EvanHerman]

Original Report: https://wordpress.org/support/topic/primer-mins-theme-featured-image-override-hero-image

We are setting the default value of use_featured_hero_image to 1 (Checked) in the customizer: https://github.com/godaddy/wp-primer-theme/blob/9c80bf4bfce4044f9af806528e305f7cad048d25/inc/customizer.php#L182-L188

But we're not referencing a default value in our get_theme_mod call: https://github.com/godaddy/wp-primer-theme/blob/21557638554f63dd2d57825e72dd68330497f02d/inc/helpers.php#L264.

This causes some confusion as it appears (based on the customizer) the featured image should replace the hero image but it does not until the customizer settings are saved.

Default value of get_theme_mod should be 1 to match the customizer default value.
eg:

get_theme_mod( 'use_featured_hero_image', 1 );