Is it possible to A/B test http/2 with http/1.1 using same domain name in Akamai?
I wouldn't recommend having both http/1.1 and http/2 on same server.
My suggestion would be perform all your testing on http/1.1 now and capture the details. Once done. You can enable http/2 and run the same testing again for comparison.
or if you can configure a separate domain for test then great.
I would say its safe to implement http/2 in akamai, to start getting the benefit of http/2 from Akamai servers to end user browser. Then you can explore on how to enable http/2 between akamai and origin server.