Refactored cell broadcast area info support

Area info cell broadcast messages are not handled
by cell broadcast receiver anymore. Instead, they will
be processed in cell broadcast service. Privileged apps
that are interested in getting the information will need
to get it directly from cell broadcast service.

Note this is only enabled for certain countries and carriers.

Test: Manual
Bug: 141318859
Bug: 141425194

Change-Id: I2245c39f679d0ad94c9a1325edc553f362fdce7c