Avoid showing roaming icon for short time after boot-up

When service state polling is not finished, IMS phone may inform
service state change under CDMA phone, so the wrong roaming indicator
is notified to UI to show unexpected icon.

To fix it, initialize the service state properly.

Bug: 79839080
Change-Id: I98e4264e1b3e190d68520b4a37f7b53d4b800337