Wifi: Create new object for accesspoints while updating in UI

Already connected AP is cached in Scanresultcache, which is causing
the AP to populate in UI even if the AP is not available in range or
if AP is switched off.
This commit ensures to remove the unavailable APs from UI.

CRs-Fixed: 930164

Change-Id: I4428d44851ca46e3328a213b2349e02e1fa31bc3