Add MDNS to the build.

Change-Id: I025fe959a38344bb072ec13701f934a4fb9a5f36
diff --git a/target/product/core.mk b/target/product/core.mk
index 732e476..ec823f0 100644
--- a/target/product/core.mk
+++ b/target/product/core.mk
@@ -85,6 +85,7 @@
     libicui18n \
     libicuuc \
     libkeystore \
+    libmdnssd \
     libnativehelper \
     libnfc_ndef \
     libpowermanager \
@@ -107,6 +108,7 @@
     libwebrtc_audio_preprocessing \
     libwilhelm \
     libz \
+    mdnsd \
     requestsync \
     screencap \
     sensorservice \