get DHCP IP on each connection

The IP state was not being refreshed when the supplicant transitions
from COMPLETED to ASSOCIATED to COMPLETED. This can lead to
a connected state with no real connection due to old IP settings.
The fix refreshes IP on each connection.

Bug: 2329261
Change-Id: I38cd56369ee2d8ab3e0f06f5c9f5712b9b2f35a0