Merge "Fix potential NPE when preference is null" am: 2b6a72ba am: b5e59833

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2256881



Change-Id: I38a063882089a767732f748e851f5cbedd1e6cab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>