Merge "Nullability check for mman module." am: b72900c5c9 am: ebd33d5977 am: c5ce34172c am: c2520bbdeb am: b2944ac673

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2580311

Change-Id: I906a897ab51468829b9d07533f3f65a5c63a24d5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>