Merge "[CS17]Remove useless code(AsyncChannel) from ConnectivityService" am: 2dafdfb0f8

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1625701

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I9096f951a18b1ffe96efa1d48207dac644d4e92c