Drop circular dependency

There was a circular dependency between net-tests-utils-host-common and
ConnectivityTestPreparer. This hasn't caught because Soong didn't track
the required dependency (ConnectivityTestPreparer requires the other).
However, as Soong is fixed to track the dependency type, this is caught
as an error.

Dropping the "required" dependency because net-tests-utils-host-common
is a host test module and is the entry point.

Bug: 321626681
Test: m
Change-Id: I539bbe2689be0af52bfec35966dd8210137d6c72
1 file changed