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
Merged-In: Ib8ac989ed521254f08c9ced9f2b12fbafd97579f
Change-Id: Ib8ac989ed521254f08c9ced9f2b12fbafd97579f
(cherry picked from commit 6d030fc8)