Create an OWNERS file in webrtc/api/audio_codecs/

So that it's easier to find the right reviewers.

NOTRY=true
BUG=none

Review-Url: https://codereview.webrtc.org/2860093005
Cr-Commit-Position: refs/heads/master@{#18037}
diff --git a/webrtc/api/audio_codecs/OWNERS b/webrtc/api/audio_codecs/OWNERS
new file mode 100644
index 0000000..a52dd93
--- /dev/null
+++ b/webrtc/api/audio_codecs/OWNERS
@@ -0,0 +1,2 @@
+kwiberg@webrtc.org
+ossu@webrtc.org