Merge "Nullability check for shm module." am: 374d2f1be0 am: 1467fed1d8 am: e26c611a2f am: 26d85c44e0

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2601525

Change-Id: Ie5c093c1646c8092d960bf81b4ecfda0dbe6df7b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>