Merge "Do not allow null signal thresholds in SignalStrengthUpdateRequest" am: b6aa5b7d37 am: 59cd9748a2 am: 14077cf279

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1894915

Change-Id: I8cc614be29038baebc2f0c42e66ced7d5d06107a