dnsmasq: fix heap overflow am: 2c415e570a am: d9b4de509f am: 35a6d0cb35 am: 5bfc7bb2fb am: ef42febf89

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/dnsmasq/+/13032295

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ia3397890fbacfaa20af881b15f724e6d3f106be4