Disable libcore test that requires IPv6

Test: N/A
Bug: 25178637
Bug: 34038136
Change-Id: I14c7451d269ee8f1163369d8c0d2209498466b66
diff --git a/tools/libcore_failures.txt b/tools/libcore_failures.txt
index 53fe8fe..dcef8c0 100644
--- a/tools/libcore_failures.txt
+++ b/tools/libcore_failures.txt
@@ -169,7 +169,8 @@
   description: "Lack of IPv6 on some buildbot slaves",
   result: EXEC_FAILED,
   names: ["libcore.io.OsTest#test_byteBufferPositions_sendto_recvfrom_af_inet6",
-          "libcore.io.OsTest#test_sendtoSocketAddress_af_inet6"],
+          "libcore.io.OsTest#test_sendtoSocketAddress_af_inet6",
+          "libcore.io.OsTest#test_recvfrom_EmptyPacket"],
   bug: 25178637
 },
 {