[automerger skipped] Fix NPE when deleting old zen rules am: 7bb9cd92bf am: 8a021141ff am: b953b5eff6 -s ours am: 1cb919e374 -s ours

am skip reason: Merged-In I069fcc124af24227fa50b61d4fc55d6dadc7a20b with SHA-1 93aa03a0db is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19202448

Change-Id: Iab15f57066387644be45f281e53731bdd8071304
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>