wifi: catch UnsupportedOperationException for getMatchingWifiConfig

On a device without Passpoint support, an UnsupportedOperationException
will be thrown when invoking WifiManager#getMatchingWifiConfig.
So catch it to avoid crash.

Bug: 36649203
Test: manually set config_wifi_hotspot2_enabled to false and verify
      Settings app doesn't crash

Change-Id: I69f37897449033da9d21edda9953ad2738f7e314