Fixing target_bitrate_bps for a FullStackTest

While refactoring, I incorrectly set the target bitrate for one of the tests to
500k instead of 2000k.

This does not fix all the perf regressions.

BUG=534220

Review URL: https://codereview.webrtc.org/1356123002

Cr-Original-Commit-Position: refs/heads/master@{#10008}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 1356ba5e6ceb7513137b4052f0c2f9edddb11d5e
1 file changed