Add OWNERS to BWE modules.

BUG=None

Review-Url: https://codereview.webrtc.org/2556703002
Cr-Original-Commit-Position: refs/heads/master@{#15550}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 4f19b2fe0973a98b352ca690ab240fa720f0fc1e
4 files changed