Run H264 instead of Youtube perf for presubmit

WidevineYouTubePerformanceTests has been flaky on cuttlefish,
e.g. http://ab/I19300007386488046.

Bug: 178816546
Test: TreeHugger
Change-Id: I889787dd22f7685bd2d22eede2d066d442c23c70
diff --git a/apex/TEST_MAPPING b/apex/TEST_MAPPING
index 09c46d6..4b7c019 100644
--- a/apex/TEST_MAPPING
+++ b/apex/TEST_MAPPING
@@ -16,7 +16,7 @@
           "include-filter": "com.google.android.media.gts.WidevineGenericOpsTests"
         },
         {
-          "include-filter": "com.google.android.media.gts.WidevineYouTubePerformanceTests"
+          "include-filter": "com.google.android.media.gts.WidevineH264PlaybackTests"
         }
       ]
     }