Bitnami servers come with Apache and WordPress SSL enabled with a self signed certificate. I will address replacing this certificate in a later post.
As I understand it Bitnami configures the AWS cloud image so that the application configuration overwrites the Apache configuration. This is described in their documentation.
The relevant section is
This will not work because it is overwritten by the WordPress configuration as highlighted. Instead you must follow these instructions,
Recent versions of BitNami apps ship three configuration files in the “/installdir/apps/myapp/conf/“ folder: httpd-app.conf, httpd-prefix.conf and httpd-vhosts.conf.
After making the required change to the application configuration file you must restart the server.
$ sudo /opt/bitnami/ctlscript.sh restart apache