Add Phone.getPhoneType() operation.

This routine returns integer values defined in the Phone interface,
derived from RILConstants values.  Direct references to the
RILConstants are replaced by references to these new ones for
consistency.

API CHANGE:
  unhide TelephonyManager.PHONE_TYPE_CDMA

Addresses issue:
http://buganizer/issue?id=1905415

Change-Id: Icfec6d457231b098c031677a66770b5e57be4a44