Followup to make sure this works with the python controller

[woody-apple]

Because we have these flags in the codebase anyway, we're already de-facto compiling with different flags. They're plumbed through gn normally, but we can compile with ex. different mdns impls etc. But I don't actually think this needs to be Ifdef'd - it seems like you can call StartServer and it will start advertising as a commissioner if that flag is on.

However, I agree with Andrei - it's unclear how you would compile the python controller to enable or disable this functionality.

Originally posted by @cecille in #9603 (comment)

[sharadb-amazon]

PR posted: #9757