Add missing defines to Bionic config. am: 4f612f6192 am: 00ca46dec0 am: 15029a9ab5

Original change: https://android-review.googlesource.com/c/platform/external/libevent/+/2808694

Change-Id: I4015861824b51c5ba29b25a634780c20ab1899bb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>