Automatically manage subdomains (without editing vhosts) apache

You can try mod-vhost-alias.

Summary
This module creates dynamically configured virtual hosts, 
by allowing the IP address and/or the Host: header of the HTTP request 
to be used as part of the pathname to determine what files to serve. 
This allows for easy use of a huge number of virtual hosts with similar configurations.

You can use VH like following:

<VirtualHost *:80>
        ServerAdmin webmaster@localhost
        VirtualDocumentRoot /var/www/%0/html

        <Directory /var/www/%0/html/>
            Options Indexes FollowSymLinks
            AllowOverride All
            Require all granted
        </Directory>

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

I tested it and it worked for me. %0 means it will substitute it with full link. So if someone goes example.example.com, it’ll use it. You can also use %1, to use only first part. For more look at above link provided.

Edit, Just to note, you need to add wildcard CNAME record @ to make desired effect.