Add logging to Intelligibility Enhancer

It logs when the IE is activated and deactivated.

R=ivoc@webrtc.org, turaj@webrtc.org

Review URL: https://codereview.webrtc.org/2104273002 .

Cr-Original-Commit-Position: refs/heads/master@{#13370}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 1aa821980d2f871336d2f323143934bb81affff6
2 files changed