Fix the Nullable pointer is dereferenced issue

The member ai_addr is allowed to be null, which will cause dereferencing nullptr
issue here.
See https://android-build.corp.google.com/artifact/pending/P54712024/aosp_arm64-userdebug/latest/view/logs%2Fbuild.log
for more details

Bug: None
Test: mm
Change-Id: Ie1e8ec56bbd1edee0456c26d0d29775bc7abbbb5