Make use of the DNS query hook in the netcontext

This will allow netd to run queries over TLS:
https://android-review.googlesource.com/#/c/391513/
https://android-review.googlesource.com/#/c/380593/

Bug: 34953048
Test: Device tests pass.  No issues during manual testing.
Change-Id: I8d613322307fc40cdba59b82599eda753697278f
diff --git a/libc/dns/resolv/res_init.c b/libc/dns/resolv/res_init.c
index b9fc131..302a62b 100644
--- a/libc/dns/resolv/res_init.c
+++ b/libc/dns/resolv/res_init.c
@@ -768,17 +768,12 @@
 }
 
 #ifdef ANDROID_CHANGES
-void res_setnetid(res_state statp, unsigned netid)
+void res_setnetcontext(res_state statp, const struct android_net_context *netcontext)
 {
 	if (statp != NULL) {
-		statp->netid = netid;
-	}
-}
-
-void res_setmark(res_state statp, unsigned mark)
-{
-	if (statp != NULL) {
-		statp->_mark = mark;
+		statp->netid = netcontext->dns_netid;
+		statp->_mark = netcontext->dns_mark;
+		statp->qhook = netcontext->qhook;
 	}
 }