ipv4 tethering offload - decrement ttl during forwarding

Bug: 192635131
Test: atest, TreeHugger, flashed on phone, forwarded ipv4 traffic
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Original-Change: https://android-review.googlesource.com/1755049
Merged-In: I88e5293a54b7867a8e7dd76f6fd8e2a52d31e51a
Change-Id: I88e5293a54b7867a8e7dd76f6fd8e2a52d31e51a
1 file changed