Merge "Nullability check for xattr module." am: 0f371ff845 am: ace1448647 am: 3dbe31412e am: 29fae2f537

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2597870

Change-Id: I0cc476c3e0c7867c4dedaf4cf92579ccffe4c07a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>