Remove old implementation of NitzStateMachine

Remove old implementation of NitzStateMachine as it has been superseded
and it is not used.

Various classes have been moved into the
com.android.internal.telephony.nitz package because they are only associated
with the one remaining implementation.

Bug: 149014708
Test: treehugger
Change-Id: I704bde1d3ca525e5325aaa89c89fba67f2bef66c