Partial refactoring telephony network factory test cases

Avoid passing DcTracker into telephony network factory's
constructor. This is the preliminary step for multiple
DcTrackers support.

Also partially refactored the telephony network
factory unit test so it adapts the existing telephony
test infrastructure.

Test: Manual + unit tests
Bug: 73659459
Change-Id: Ib8ac989ed521254f08c9ced9f2b12fbafd97579f