ACM: Removing runtime APIs related to playout mode

The playout mode in NetEq can still be set through the constructor
configuration.

BUG=webrtc:3520

Review URL: https://codereview.webrtc.org/1362943004

Cr-Original-Commit-Position: refs/heads/master@{#10089}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 1bd0e03ce56ed5384c3377b6da171951ec654706
11 files changed