audio flinger: report actual sink device for MSD playback threads

When a playback thread is routed to an MSD module, make sure that the
actual sink device selected by the software patch at the output of the
MSD module is reported to AudioTrack clients.

Bug: 139894721
Test: atest AudioTrackTest
Test: atest RoutingTest
Change-Id: Ie52ebe198e9ebdfe5f2a38dcd44c551c705a7931
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 1cf1e67..1c6f57c 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -292,6 +292,9 @@
     status_t removeEffectFromHal(audio_port_handle_t deviceId,
             audio_module_handle_t hwModuleId, sp<EffectHalInterface> effect);
 
+    void updateDownStreamPatches_l(const struct audio_patch *patch,
+                                   const std::set<audio_io_handle_t> streams);
+
 private:
     // FIXME The 400 is temporarily too high until a leak of writers in media.log is fixed.
     static const size_t kLogMemorySize = 400 * 1024;