Update UID routing to upstream implementation.

This is essentially a revert of our out-of-tree changes plus
upstream 82252cdc ("ip: support UID range routing.").

Test: netd_integration_test passes on a device with updated kernel
Test: added, deleted, listed, and looked up rules manually on a device with updated kernel
Bug: 16355602
Change-Id: I1767580daf51913886a43dd45bafbee97550091e
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>