[DO NOT MERGE] fingerprint: handle PerformanceStats NULL pointers am: 3615be74c1 am: eea53b512c am: 3f78dbf336 am: 42d8fb924c

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1439198

Change-Id: Id5accd254cbc3439e47f47c77e1b8db8f29c93f9