[Telemetry] Disable tough_video_cases on the Android L release.

It hangs on reliably audio_playback.html?id=mixed_audio on a Nexus 7 v2.

BUG=389362
NOTRY=True
TBR=shadi@chromium.org

Review URL: https://codereview.chromium.org/388883003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282691 0039d316-1c4b-4281-b951-d872f2087c98

tools/perf/benchmarks/media.py

@@ -44,6 +44,7 @@ class MediaNetworkSimulation(benchmark.Benchmark):
 
 
 @benchmark.Enabled('android')
+@benchmark.Disabled('l')
 class MediaAndroid(benchmark.Benchmark):
   """Obtains media metrics for key user scenarios on Android."""
   test = media.Media