Merge "Make NattKeepalivePacketData @SystemApi" am: 9fef5a5cf0 am: 6426059fa3 am: 2be2e8d19f

Change-Id: Idd26f3118e879ab05a8cdd23a9e4999b3bafbf47
tree: 0480bb3f5ff4b82ff5ab23b3e48761e10a1eecc4
  1. core/
  2. services/
  3. tests/