Hmmm you’re right can’t seem to give any permission to the microphone on any browser 
I also do think you’re right about the HTTP and not local, as described in google chrome - Browser says "Camera Blocked to protect your privacy" - Stack Overflow. But even setting the flag to treat insecure origin as secure did not work for me.
If you can, I’d reverse proxy your Streamlit app endpoints through an NGINX/Apache (there are topics on this in the forum Streamlit, docker, Nginx, ssl/https - #5 by agray ) and rollout a self-signed Let’s encrypt certificate to get HTTPS. I’m not an AWS user but maybe AWS does provide with ways to reverse proxy, maybe it’s described in one of the following tutorials: Streamlit Deployment Guide (wiki).