Add Social Media Icon to Header in a child theme

I have followed the directions to add the social media icon as described in this post:
https://kriesi.at/support/topic/add-social-media-icon-to-header/

But won’t this get lost every time I update the theme?

I tried tried adding this whole block of code to functions.php in my child theme folder but it did not work.

$avia_config['font_icons'] = apply_filters('avf_default_icons', array(
 
    //post formats +  types
    'standard' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue836'),
    'link'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue822'),
    'image'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue80f'),
    'audio'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue801'),
    'quote'   		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue833'),
    'gallery'   	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue80e'),
    'video'   		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue80d'),
    'portfolio'   	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue849'),
    'product'   	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue859'),
    				
    //social		
    'behance' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue915'),
	'dribbble' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8fe'),
	'facebook' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8f3'),
	'flickr' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8ed'),
	'gplus' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8f6'),
	'linkedin' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8fc'),
	'yelp' 			=> array( 'font' =>'fontello', 'icon' => 'ue800'),
	'instagram' 	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue909'),
	'pinterest' 	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8f8'),
	'skype' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue90d'),
	'tumblr' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8fa'),
	'twitter' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8f1'),
	'vimeo' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8ef'),
	'rss' 			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue853'),  
	'youtube'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue921'),  
	'xing'			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue923'),  
	'soundcloud'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue913'),  
	'five_100_px'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue91d'),  
	'vk'			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue926'),  
	'reddit'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue927'),  
	'digg'			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue928'),  
	'delicious'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue929'),  
	'mail' 			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue805'),
					
	//woocomemrce    
	'cart' 			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue859'),
	'details'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue84b'),

	//bbpress    
	'supersticky'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue808'),
	'sticky'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue809'),
	'one_voice'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue83b'),
	'multi_voice'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue83c'),
	'closed'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue824'),
	'sticky_closed' => array( 'font' =>'entypo-fontello', 'icon' => 'ue808\ue824'),
	'supersticky_closed' => array( 'font' =>'entypo-fontello', 'icon' => 'ue809\ue824'),
					
	//navigation, slider & controls
	'play' 			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue897'),
	'pause'			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue899'),
	'next'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue879'),
    'prev'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue878'),
    'next_big'  	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue87d'),
    'prev_big'  	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue87c'),
	'close'			=> array( 'font' =>'entypo-fontello', 'icon' => 'ue814'),
	'reload'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue891'),
	'mobile_menu'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8a5'),
					
	//image hover overlays		
    'ov_external'	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue832'),
    'ov_image'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue869'),
    'ov_video'		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue897'),
    
					
	//misc			
    'search'  		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue803'),
    'info'    		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue81e'),
	'clipboard' 	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue8d1'),
	'scrolltop' 	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue876'),
	'scrolldown' 	=> array( 'font' =>'entypo-fontello', 'icon' => 'ue877'),
	'bitcoin' 		=> array( 'font' =>'entypo-fontello', 'icon' => 'ue92a'),

));

Then there is still the matter of the code added to:
includes > admin > register-admin-options.php

Can you please give a brief tutorial for adding the Social Media Icon to the child theme so that it will not be overwritten when the theme is updated?