Merge "Expose SignalThresholdInfo as public class" am: a40d0d19f1 am: 239b7f35c0 am: fa9b9b877d

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1543601

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib9b6e4dbe2f248d00215773b87b5d6d04033d4fc