Merge "AudioMixer: Always do prepareForReformat() in setChannelMasks()" into pi-dev

    // channel masks have changed, does this track need a downmixer?

    // update to try using our desired format (if we aren't already using it)

    const audio_format_t prevDownmixerFormat = track->mDownmixRequiresFormat;

    const status_t status = track->prepareForDownmix();

    ALOGE_IF(status != OK,

            "prepareForDownmix error %d, track channel mask %#x, mixer channel mask %#x",

            status, track->channelMask, track->mMixerChannelMask);

    if (prevDownmixerFormat != track->mDownmixRequiresFormat) {

        track->prepareForReformat(); // because of downmixer, track format may change!

    }

    // always do reformat since channel mask changed,

    // do it after downmix since track format may change!

    track->prepareForReformat();

    if (track->mResampler.get() != nullptr && mixerChannelCountChanged) {

        // resampler channels may have changed.