Merge "Use index mask when there is no valid input mask from output mask." am:...

        using namespace std::chrono_literals;

        auto inChannelMask = audio_channel_mask_out_to_in(track->channelMask());

        if (inChannelMask == AUDIO_CHANNEL_INVALID) {

            // The downstream PatchTrack has the proper output channel mask,

            // so if there is no input channel mask equivalent, we can just

            // use an index mask here to create the PatchRecord.

            inChannelMask = audio_channel_mask_out_to_in_index_mask(track->channelMask());

        }

        sp patchRecord = new RecordThread::PatchRecord(nullptr /* thread */,

                                                       track->sampleRate(),

                                                       inChannelMask,