Remove the system API of getCarrierBandwidth()

Remove the system API of getCarrierBandwidth() and CarrierBandwidth as
they are replaced by the new LCE system API in PhoneStateListener.

Bug: 176814680
Test: atest -c PhoneStateListenerTest
Change-Id: I0cc020ba39abebb19c828dcfd4710592141ea637
1 file changed