This PR switches the Plex container to use host networking instead of bridge networking. This fixes two issues:
1) It solves the port clash issue with Home Assistant. Previously, if a user tried to install Plex after installing Home Assistant (but not the other way around) the explicit mapping of port 1900 in the Plex compose file would cause Docker to error because port 1900 would be in use by Home Assistant for SSDP discovery and uPNP. Both apps now use the hosts network stack and don't explicitly bind ports, so Docker will not error and they can successfully share the udp port.
2) DLNA server access in Plex will actually work. DLNA server access doesn't work in bridge network mode by default, because udp multicast packets are not automatically forwarded from the host network stack to the bridge network stack.
This PR switches the Plex container to use host networking instead of bridge networking. This fixes two issues: 1) It solves the port clash issue with Home Assistant. Previously, if a user tried to install Plex after installing Home Assistant (but not the other way around) the explicit mapping of port 1900 in the Plex compose file would cause Docker to error because port 1900 would be in use by Home Assistant for SSDP discovery and uPNP. Both apps now use the hosts network stack and don't explicitly bind ports, so Docker will not error and they can successfully share the udp port. 2) DLNA server access in Plex will actually work. DLNA server access doesn't work in bridge network mode by default, because udp multicast packets are not automatically forwarded from the host network stack to the bridge network stack.