Remove |hw_encoder| and |hw_decoder| from VideoCodecTestFixture::Config.

Only used for output filename nowadays. Previously, it was used for
selecting the codec implementation. That is now done by injecting
the appropriate codec factory.

Bug: webrtc:9317
Change-Id: Ia2bf28f7df165fb65410ecd1f5d646ee6604e1be
Reviewed-on: https://webrtc-review.googlesource.com/c/106023
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25204}

modules/video_coding/codecs/test/videocodec_test_libvpx.cc

@@ -63,8 +63,6 @@ VideoCodecTestFixture::Config CreateConfig() {
   config.filepath = ResourcePath(config.filename, "yuv");
   config.num_frames = kNumFramesLong;
   config.use_single_core = true;
-  config.hw_encoder = false;
-  config.hw_decoder = false;
   return config;
 }