Merge "Do not allow null signal thresholds in SignalStrengthUpdateRequest" am: b6aa5b7d37 am: 59cd9748a2 am: 14077cf279 am: 62cedb85b9

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

Change-Id: I2055309b555c2c42f69ecae9b585c27fce2ed252