Migrate wifi tests out of NetworkAgent Messenger am: d17d2418eb am: a47639c79d

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Wifi/+/1540864

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibe1ce3d01849b2e7a17361f2b2160b6ee871d4c2