netd: NetlinkManager: add support receiving quota2 log messages

NetlinkManager, NetlinkHandler
 . added support for netlink's NETLINK_NFLOG family used by the updated xt_quota2.
 . it pushes the event all the wait to NetworkManagementService.java
    "linit alert <alert_name> <iface_name>"

This needs:
 - new kernel with quota2 changes that support logging via NETLINK's
   NETLINK_NFLOG family.
 - BandwidthController changes that setup the alerts.
 - system core NetlinkEvent that recognizes the NFLOG messages.
 - java land NetworkManagementService changes.

Change-Id: Id5b1026c6002803b5a1c0c7623cf7b1961de9802
5 files changed