Merge "Nullability correction for stdlib module." am: 9a3164145c

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2510535

Change-Id: I1f5c1fd3c474408a20115550442a15e57be1a797
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>