msm: netfilter: NATTYPE Refresh Timer Changes

NATTYPE entry timeout will not be updated when packets
start flowing through IPA and eventually can timeout.
Make changes to refresh the NATTYPE entry timeout from
the connection tracking netlink module which is used by
IPANAT to update conntrack timeout. Also make the timeout
dynamic by taking the expiry timeout value from connection
tracking entry. Otherwise NATTYPE entry will not timeout
even when all the corresponding conntrack entries expire.

Also, This change take care of porting of below changes
1) netfilter: Add of NATTYPE COOKIE Check
I1a53fa0dc6961dd3e53d382642b413d4ee781ed6
2)ipt_NATTYPE: Fix for changes in
I31e4c4acae30378f37bd4b8e4d7d617957a0545d
3)netfilter: Move NATTYPE forward mode to POSTROUTING chain.
Ic03436339e2b0a6c4277146942f518e6c7d49574

CRs-FIXED: 490813
Change-Id: Ibb225d7b91070ca9948c7a11f0b5925a8435915c
Acked-by: Suraj Jaiswal <c_surajj@qti.qualcomm.com>
Signed-off-by: Tyler Wear <twear@codeaurora.org>
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>