Phone refactor Phase II. Renamed PhoneBase to Phone.

Phone interface has been renamed to PhoneInternalInterface. For
outside world, Phone is now the only handle that should be used
for phone related classes (earlier there were Phone, PhoneBase,
GSMPhone, etc.). Some cleanup is still pending to make sure
technology specific phone is not used outside of telephony at all
(and even within telephony as much as possible).

Bug: 25793157
Change-Id: Ic19b286e6d2580e5537f4f6a8dc8afe39d80a803