Change the previous GN configs to build GYP instead
(since we'll keep GYP around for a while) but exclude tests for
that config from now on, since we're facing errors with GYP.
Add new configs for upcoming rename of those bots to GYP instead
of GN.
BUG=webrtc:5949
NOTRY=True
Review-Url: https://codereview.webrtc.org/2264283003
Cr-Commit-Position: refs/heads/master@{#13875}