[nearby] Catches NPE in ChreDiscoveryProvider am: e899d26468 am: ebbfeee740

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2871061

Change-Id: I38deae29eae221ca76d4c5aa892ecd956c31c0c8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>