Add missing SHARED_SECRET env var + entry in /etc/hosts for reverse proxy

[bed007]

Add missing SHARED_SECRET env var for premium deployment using headwindmdm/hmdm docker image.

Add hostAliases mapping when ingress is enabled to resolve uri on baseDomain to the reverse proxy ip as documented here: https://qa.h-mdm.com/1/installed-the-system-but-qr-code-is-not-showing

With these two changes, I am able to deploy on an existing AKS cluster.