Audioflinger dumpsys: Use libjsoncpp for json dump

Test: dumpsys media.audio_flinger --json
Bug: 68148948
Change-Id: Ieebe2c52e3613e48a5ec5cbb2b1f167a32d5a47d
diff --git a/services/audioflinger/Android.mk b/services/audioflinger/Android.mk
index c0aa477..2c26ba4 100644
--- a/services/audioflinger/Android.mk
+++ b/services/audioflinger/Android.mk
@@ -42,6 +42,7 @@
 
 LOCAL_STATIC_LIBRARIES := \
     libcpustats \
+    libjsoncpp \
     libsndfile \
 
 LOCAL_MULTILIB := $(AUDIOSERVER_MULTILIB)