Add resolv_res_nsend

Add public function resolv_res_nsend which would call res_nsend directly.
This function will be used by DNS-Async API.

Test: built, flashed, booted

Change-Id: I81cead2ea00e7e6f738fc0b3eef12a036a10fc7c
diff --git a/resolv/include/netd_resolv/resolv.h b/resolv/include/netd_resolv/resolv.h
index 981340a..134725a 100644
--- a/resolv/include/netd_resolv/resolv.h
+++ b/resolv/include/netd_resolv/resolv.h
@@ -110,6 +110,11 @@
                                                            const addrinfo*,
                                                            const android_net_context*, addrinfo**);
 
+// Query dns with raw msg
+// TODO: Add a way to control query parameter, like flags, or maybe res_options or even res_state.
+LIBNETD_RESOLV_PUBLIC int resolv_res_nsend(const android_net_context* netContext, const u_char* msg,
+                                           int msgLen, u_char* ans, int ansLen, int* rcode);
+
 // Set name servers for a network
 LIBNETD_RESOLV_PUBLIC int resolv_set_nameservers_for_net(unsigned netid, const char** servers,
                                                          unsigned numservers, const char* domains,