Merge "Nullability check for socket module." am: 0181dd9f05

Original change: https://android-review.googlesource.com/c/platform/bionic/+/2605708

Change-Id: I2f88520dbbfac04a0e50d78c9e590c894e827b62
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>