Use connectivity APIs from framework-connectivity

Instead of compiling framework-connectivity source into
frameworks-minus-apex, have the APIs loaded separately from
framework-connectivity.

Bug: 171540887
Test: device boots, has connectivity
Change-Id: I8f07ff2082c3de80821e121807e66a43a870de7b

framework/src/android/net/NetworkUtils.java

@@ -42,6 +42,9 @@ import java.util.TreeSet;
  * {@hide}
  */
 public class NetworkUtils {
+    static {
+        System.loadLibrary("framework-connectivity-jni");
+    }
 
     private static final String TAG = "NetworkUtils";