[automerger] audio: ensure effect chain with specific session id is unique am:...

            }

            // look for the thread where the specified audio session is present

            for (size_t i = 0; i < mPlaybackThreads.size(); i++) {

                if (mPlaybackThreads.valueAt(i)->hasAudioSession(sessionId) != 0) {

                uint32_t sessionType = mPlaybackThreads.valueAt(i)->hasAudioSession(sessionId);

                if (sessionType != 0) {

                    io = mPlaybackThreads.keyAt(i);

                    // thread with same effect session is preferable

                    if ((sessionType & ThreadBase::EFFECT_SESSION) != 0) {

                        break;

                    }

                }

            }

            if (io == 0) {

                for (size_t i = 0; i < mRecordThreads.size(); i++) {

                    if (mRecordThreads.valueAt(i)->hasAudioSession(sessionId) != 0) {