This change adds implementation details for add/remove addresses onto a VTI. Bug: 73675031 Test: New tests added, passing on Walleye Merged-In: Idde9d943a5285d2c13c5c6b0f7b8a9faf718e6a5 Change-Id: Idde9d943a5285d2c13c5c6b0f7b8a9faf718e6a5 (cherry picked from commit ecc9f7cc08804e3fa15fea04ae94ea1bc74edbfe)