Increase the SO_SNDBUF for statsd socket.

In addition to the dgram queue size, the sender buffer size also matters.
Set it to a higher value (default is 224KB).

Test: manual
Change-Id: Ib610c1fa1eaf3c5e36f51854a2b0720f387dc1b8
diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
index b778f92..b1c05ea 100644
--- a/libstats/statsd_writer.c
+++ b/libstats/statsd_writer.c
@@ -109,6 +109,11 @@
         if (sock < 0) {
             ret = -errno;
         } else {
+            int sndbuf = 1 * 1024 * 1024;  // set max send buffer size 1MB
+            socklen_t bufLen = sizeof(sndbuf);
+            // SO_RCVBUF does not have an effect on unix domain socket, but SO_SNDBUF does.
+            // Proceed to connect even setsockopt fails.
+            setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &sndbuf, bufLen);
             struct sockaddr_un un;
             memset(&un, 0, sizeof(struct sockaddr_un));
             un.sun_family = AF_UNIX;