callforwarding: Re-arrange call forward indicator

IccRecords is checked in setVoiceCallForwardingFlag API.
So no needs null check each cases.
Support call forwarding indicator for IMS, too.

Bug: 146532578

Change-Id: I9d4c3403931e36cff4b02bd43717a5e91562fef5
Signed-off-by: Jang Hayeong <hayeong.jang@samsung.com>