Add AIDL parcelable for NattKeepalivePacketData

Bug: 33530442
Test: atest FrameworksNetTests

Change-Id: I9b9a51dc5dc06c90229fb36c34c24258991c4146
Merged-In: I9b9a51dc5dc06c90229fb36c34c24258991c4146
(cherry picked from commit 76985bd9a5577fb905e45b20513661ee10c1f44f)
3 files changed