[M126-LTS] ipcz: Validate link state fragment before adoption

(cherry picked from commit c333ed99)

Fixed: 368208152
Change-Id: I0e2ece4b0857b225d229134b2e55abc3e08348ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5876623


Commit-Queue: Ken Rockot <rockot@google.com>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1358968}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5901253


Owners-Override: Artem Sumaneev <asumaneev@google.com>
Reviewed-by: Artem Sumaneev <asumaneev@google.com>
Commit-Queue: Gyuyoung Kim (xWF) <qkim@google.com>
Cr-Commit-Position: refs/branch-heads/6478@{#1983}
Cr-Branched-From: e6143acc-refs/heads/main@{#1300313}