Add an API to access the CDMAPhone/GSMPhone call tracker state for DCTracker to check

As concurrent voice/data is not supported for all RATs, the DCTracker checks
the default phone's call state through getState API as one of the conditions
to set up data call.
For device supports VOLTE, the default phone's getState reflects the
default phone(CDMAPhone/GSMPhone) and IMS phone call state.
So the data call can't set up if the VOLTE call is in progress.
As IMSPhone call state should not impact the data call setup, this CL is
to add an API to access the CDMAPhone/GSMPhone call tracker state for
DCTracker to check.

Bug: 19090488
Change-Id: I96bb29f80d81fa6b39e2e05f1d7f47a72244ed9b