memunreachable: prevent forking when main thread times out am: 0b1e8d31d2 am: b796351312

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/memory/libmemunreachable/+/18358671

Change-Id: Ie82cf8ccb85010c57dfb6636d5e387a20f4bc083
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>