Disable FullStackTest.SimulcastFullHdOveruse on Mac

This test was added in "Add cropping to VIEEncoder to match simulcast streams resolution (https://codereview.webrtc.org/2936393002) and makes
webrtc_perf_tests fail+timeout on Mac:
https://build.chromium.org/p/client.webrtc.perf/builders/Mac%2010.11/builds/2896

[ RUN      ] FullStackTest.SimulcastFullHdOveruse
- Uh, I'm-I'm not quite dead, sir.
- Uh, I-I think uh, I could pull through, sir.
../../webrtc/video/video_quality_test.cc:419: Failure
Expected: (frames_processed) > (last_frames_processed), actual: 591 vs 591
Analyzer stalled while waiting for test to finish.

TBR=sprang@webrtc.org,magjed@webrtc.org,ilnik@webrtc.org
BUG=webrtc:7375, webrtc:6958
NOTRY=True

Review-Url: https://codereview.webrtc.org/2960573002
Cr-Original-Commit-Position: refs/heads/master@{#18748}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 7790e8779d8965107d625e1fc894e21fece150dd
1 file changed