Telephony: Call forwarding icon is shown after powerup

If call forwarding was enabled, then the call forwarding
icon should be shown after the phone has powered down and
powered-up. Added a preference parameter to store the icon
status, in case it is not updated correctly by the network
operator.

Change-Id: I06ae47c8decae64807de78461382ca746900a8dd
CRs-Fixed: 275722
(cherry picked from commit e59de9c0944ccd8cc46dab1b03c95e965c670040)
(cherry picked from commit 8989aaf096fb9141277ae5ab483abbb887f7f452)