Add more SKV Android flakes

This CL adds another flaky test to the list of SkiaVulkan Android flakes
on content_browsertests.

Bug: 977669
Change-Id: I8ba25d0dbad62f22bdab29efc81a6928035c51ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1675226
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672055}

testing/buildbot/filters/gpu.skiarenderer_vulkan_content_browsertests.filter

@@ -9,6 +9,7 @@
 -File/MediaTest.VideoBearMp4/0
 -File/MediaTest.VideoTulipWebm/0
 -Http/MediaTest.VideoBearMp4/0
+-Http/MediaTest.VideoBearSilentMp4/0
 -Http/MediaTest.VideoTulipWebm/0
 -MediaColorTest.Yuv420pTheora
 -MediaColorTest.Yuv420pVp8