Add netd binds for clearing DNS interface maps

Add resolver clearifacemapping to clear both the uidrange => interface DNS map
and the pid => interface DNS map

Change-Id: I144f4d092780b532633d8a956f68a6888d46797a
diff --git a/ResolverController.cpp b/ResolverController.cpp
index 90c0e2b..e61fae7 100644
--- a/ResolverController.cpp
+++ b/ResolverController.cpp
@@ -112,3 +112,14 @@
 
     return _resolv_clear_iface_for_uid_range(uid_start, uid_end);
 }
+
+int ResolverController::clearDnsInterfaceMappings()
+{
+    if (DBG) {
+        ALOGD("clearInterfaceMappings\n");
+    }
+    _resolv_clear_iface_uid_range_mapping();
+    _resolv_clear_iface_pid_mapping();
+
+    return 0;
+}