Merge "Split out NetworkPriorityClassifier and UnderlyingNetworkRecord" am: 42bf9da702 am: 1baad423a7

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1901030

Change-Id: Iee6b801ecb6cc42c1bc2dff0de9b2e976624d823