Merge "Nullability check for sched module." am: 0fec9c0e19

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2496358

Change-Id: I624e72ad83ea7829cf66aec5e7710b73633bd8be
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>