shill: increase DNS attempts parameter from 2 to 5

The resolver in glibc defaults to a timeout of 5 seconds,
and two tries. Since we're using a shorter timeout (1 second),
increase the number of tries. That will allow us the same
amount of total time (as the default configuration) before
giving up.

BUG=chromium:177558
TEST=unit tests

Change-Id: I17bfc6a073adc2ea22ea96a9d263aa32a57e5300
Reviewed-on: https://gerrit.chromium.org/gerrit/46945
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: mukesh agrawal <quiche@chromium.org>
Tested-by: mukesh agrawal <quiche@chromium.org>
diff --git a/resolver_unittest.cc b/resolver_unittest.cc
index bafcd05..8ffdab9 100644
--- a/resolver_unittest.cc
+++ b/resolver_unittest.cc
@@ -30,12 +30,12 @@
   "nameserver 8.8.8.8\n"
   "nameserver 8.8.9.9\n"
   "search chromium.org google.com\n"
-  "options single-request timeout:1\n";
+  "options single-request timeout:1 attempts:5\n";
 const char kExpectedIgnoredSearchOutput[] =
   "nameserver 8.8.8.8\n"
   "nameserver 8.8.9.9\n"
   "search google.com\n"
-  "options single-request timeout:1\n";
+  "options single-request timeout:1 attempts:5\n";
 }  // namespace {}
 
 class ResolverTest : public Test {