WifiController: Minor cleanups

a) Location mode check should use LocationManager.isLocationEnabled()
API. The previously used global setting has been deprecated.
b) Remove unused mNetworkInfo variable & stop listening to
NETWORK_STATE_CHANGED broadcast that was used to update mNetworkInfo.

Bug: 130766132
Test: Device boots & connects to wifi network.
Test: Regression testing.
Change-Id: I173f66fa408267c0912aff6fda16993880c8d141
4 files changed