ANDROID: netfilter: xt_IDLETIMER: time-stamp and suspend/resume handling.

Message notifications contains an additional timestamp field in nano seconds.
The expiry time for the timers are modified during suspend/resume.
If timer was supposed to expire while the system is suspended then a
notification is sent when it resumes with the timestamp of the scheduled expiry.

Removes the race condition for multiple work scheduled.

Bug: 13247811

Change-Id: I752c5b00225fe7085482819f975cc0eb5af89bff
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>

[AmitP: Folded following android-4.9 commit changes into this patch
        13e257eaa624 ("nf: Remove compilation error caused by e8430cbed3ef15fdb1ac26cfd020e010aa5f1c35")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>