Adding UNPROCESSED to the available audio_sources

bug: 25564291
Change-Id: I86d8feda4d687352f98b640819211207a06d6b50
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 7c9b81e..381ce92 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -527,6 +527,7 @@
     case AUDIO_SOURCE_VOICE_RECOGNITION:    return "voice recognition";
     case AUDIO_SOURCE_VOICE_COMMUNICATION:  return "voice communication";
     case AUDIO_SOURCE_REMOTE_SUBMIX:        return "remote submix";
+    case AUDIO_SOURCE_UNPROCESSED:          return "unprocessed";
     case AUDIO_SOURCE_FM_TUNER:             return "FM tuner";
     case AUDIO_SOURCE_HOTWORD:              return "hotword";
     default:                                return "unknown";