Listen to xt_quota2 kobject event for quota

Allow quota limit reached notification to originate from both
qlog and xt_quota2 subsystem.  On 3.18 Kernel, modify xt_quota2
module to broadcast the Netlink notification via kobject.

Change-Id: Iaafe521e455d658ed8a2f95fb5114b029323d5ef
CRs-Fixed: 1008025
Bug: 24140541
diff --git a/server/NetlinkManager.cpp b/server/NetlinkManager.cpp
index 76af46f..769a80a 100644
--- a/server/NetlinkManager.cpp
+++ b/server/NetlinkManager.cpp
@@ -142,7 +142,7 @@
 
     if ((mQuotaHandler = setupSocket(&mQuotaSock, NETLINK_NFLOG,
             NFLOG_QUOTA_GROUP, NetlinkListener::NETLINK_FORMAT_BINARY, false)) == NULL) {
-        ALOGE("Unable to open quota socket");
+        ALOGW("Unable to open qlog quota socket, check if xt_quota2 can send via UeventHandler");
         // TODO: return -1 once the emulator gets a new kernel.
     }