Introduce netd_client, a dynamic library that talks to netd.

(cherry picked from commit 440de6b9f715cb18b8ee888c58d5c7a659ff5073)

Change-Id: Ib6198e19dbc306521a26fcecfdf6e8424d163fc9
diff --git a/target/product/base.mk b/target/product/base.mk
index 8aa3bc0..0bc1366 100644
--- a/target/product/base.mk
+++ b/target/product/base.mk
@@ -56,6 +56,7 @@
     libmedia_jni \
     libmediaplayerservice \
     libmtp \
+    libnetd_client \
     libnetlink \
     libnetutils \
     libpac \