[automerger skipped] Switch hwasan from fork to vfork. am: 023b3e8f10 -s ours am: 7a107ea432 -s ours

am skip reason: Merged-In I15d32829806f605d5599d776753bc32df0494661 with SHA-1 126f2f9192 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/libcore/+/15730809

Change-Id: Iad0606aea837f103fee783ee8cbc02eb72359777