Merge "Use IPV6_MIN_MTU from NetworkConstants in Ikev2Vpn" am: 75304108e7 am: 8f85ecd1f5

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1512879

Change-Id: I516719d803ccd2b4cda91eb38ecd108babab50b8