[automerger skipped] Add a null pointer check to the VcnConfig am: feab41aa -s ours am: 408f03de -s ours am: 77c07cdd -s ours

am skip reason: Merged-In I0cbab6e38f68d8c669db2ddb324b013baa93204a with SHA-1 b5ec6791 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23621625



Change-Id: I3bf8fda275797341061c8e6347100724c05858d8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>