Enhance Cell Location Api.

To boost accurary and enhance capability of cell location api,
two new APIs, TelephonyManager.getAllCellInfo() and
TelephonyManager.listen(LISTEN_CELL_INFO), are added. Two new
Class, CellInfo and CellIdentity, are created.

This API change returns all information of one cell locaiton
at the same time. It also provides additional LTE and timestamp information.

Change-Id: I4d0f813107e625ec4ac88c8d980ffd171aa5fc30