Create ImsService API compat layer

Creates a new ImsService API compat layer,
which translates the "new" API to the
"old" API in the android.telephony.ims.compat
namespace to support older versions of
ImsService Implementation

Bug: 63987047
Test: Manual, Telephony unit tests
Merged-In: I7daafe2ac150c49ba4ad8f08ac175eb7e6044633
Change-Id: I7daafe2ac150c49ba4ad8f08ac175eb7e6044633