Rematch wifi networks when the avoid bad wifi setting changes.

Currently, when the avoid bad wifi setting changes, we rematch
all networks and requests, but do not update any NetworkFactories
with new scores. This means that if a wifi network's score goes
down as a result of enabling bad wifi avoidance, we will not look
for another network (e.g., cell data) to satisfy its requests.

This makes it so that when the user enables avoiding bad wifi,
we will attempt to bring up cell data will if it is not already
connected.

Bug: 31075769
Change-Id: Ie5b685be8676999adea8c9ecbbc1abb92f81a74f