If I understood it right, accordingly to Apache Http Components last releases, there's still no compliance with SPDY nor HTTP/2 standards, even on HC 5, but there's a work force on the run to provide this (ref.: https://whimsy.apache.org/board/minutes/HttpComponents.html)
Best guess would be to use Jetty implementation within a BeanShell Sampler. Hope there's someone who have already done this.
