Change name of libipchecksum to libip_checksum am: a8106a2e am: a218915f am: 61949b4c am: cbe763a7

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/1921557

Change-Id: Ief1e3a6ea2ce60fac73667d15b14204fff036bc7