[automerger skipped] AT&T/Cricket/FirstNet use lower of IPv4/IPv6 MTU values am: e7079f6ad3 am: ec9f0cf83b am: 30d1776562 am: d0075d8b45 -s ours

am skip reason: Change-Id I78cd3d9e570aa27c042786ea3403f141e8a333ab with SHA-1 0a38bc8e3c is in history

Original change: https://android-review.googlesource.com/c/platform/packages/apps/CarrierConfig/+/1402394

Change-Id: I7ef93880aa7d80d5a97a8e3389f50f8ebd336cf8