Bringing your own trust store to system https libraries is not often supported. Especially when you get into kinds of embedded environments Netflix supports. You also might not have the capability to bring your own TLS library either. If it's a limited environment, you might only get reasonable performance if you use the system ciphers, and they may not be exposed as primitives, and x.509 parsing takes up a lot of code space in the likely event that you've got limitations there too.
In most environments you have to use the built in libraries for network connectivity, so you have to use their trust stores. Also space is very limited for the client, so you can't just put everything into it.
Was creating your own certificate authority and pinning it in the app not an option?