Telephony: Fix NT_MODE case statements.

These changes are necessary because of a RIL bug. Network Mode 7 is
LTE/CDMA for Verizon, which maps to the const NT_MODE_GLOBAL. This
allows the network mode to be changed.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I7dae0684e475f3ffd33f767088a6de13c36caaa7