Merge "[FUI20] Expose UnderlyingNetworkInfo as system Api" am: 75b50a5c73 am: ce1b075b2b

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1563496

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2cb57c40fd5679dbd710396f3c69deafbac9d1c3