Value 10 seems to be too small for some implementations. Updates the value to 20. This affects VideoCodecTestFixture. Bug: None Change-Id: Ibbeb7cb5ef23f8ac625d37aaa764c9d245f23e9d Reviewed-on: https://webrtc-review.googlesource.com/87562 Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Commit-Queue: Sami Kalliomäki <sakal@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23882}