Alex: Disable auto-mute and add AutoUnplugInputNode flag

Chrome will select the output device now. Also turn on
AutoUnplugInputNode flag to display only the active input
device on UI.

BUG=chromium:267355
TEST=Manual test on x86-alex, gmerge adhd; select
output device in Chrome UI

Change-Id: I6d4b1aa4aa059c6d9e2ec5ce10fca43388b2b03b
Reviewed-on: https://gerrit.chromium.org/gerrit/66094
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Hsinyu Chao <hychao@chromium.org>
Tested-by: Hsinyu Chao <hychao@chromium.org>
1 file changed