Replace android_open_proxy with dns_open_proxy

remove android_open_proxy and use dns_open_proxy instead of it.
dns_open_proxy is in libnetd_client and
it does the same thing as android_open_proxy except return value.
It returns fd directly now.

Test: build, dns works fine
Change-Id: I984743fb50b23eeb9a7d24e9fc347832acfe2afe
diff --git a/libc/bionic/NetdClient.cpp b/libc/bionic/NetdClient.cpp
index a5c519e..87eec27 100644
--- a/libc/bionic/NetdClient.cpp
+++ b/libc/bionic/NetdClient.cpp
@@ -58,6 +58,8 @@
     netdClientInitFunction(netdClientHandle, "netdClientInitNetIdForResolv",
                            &__netdClientDispatch.netIdForResolv);
     netdClientInitFunction(netdClientHandle, "netdClientInitSocket", &__netdClientDispatch.socket);
+    netdClientInitFunction(netdClientHandle, "netdClientInitDnsOpenProxy",
+                           &__netdClientDispatch.dnsOpenProxy);
 }
 
 static pthread_once_t netdClientInitOnce = PTHREAD_ONCE_INIT;
diff --git a/libc/bionic/NetdClientDispatch.cpp b/libc/bionic/NetdClientDispatch.cpp
index 67fa197..a873173 100644
--- a/libc/bionic/NetdClientDispatch.cpp
+++ b/libc/bionic/NetdClientDispatch.cpp
@@ -30,6 +30,10 @@
     return netId;
 }
 
+static int fallBackDnsOpenProxy() {
+    return -1;
+}
+
 // This structure is modified only at startup (when libc.so is loaded) and never
 // afterwards, so it's okay that it's read later at runtime without a lock.
 __LIBC_HIDDEN__ NetdClientDispatch __netdClientDispatch __attribute__((aligned(32))) = {
@@ -37,4 +41,5 @@
     __connect,
     __socket,
     fallBackNetIdForResolv,
+    fallBackDnsOpenProxy,
 };