[Wi-Fi] Fix exception when clicking About phone -> Wi-Fi MAC address

From android R, SavedAccessPointsWifiSettings2 is added for WifiTrackerLib,
SavedAccessPointsWifiSettings is deprecated.

From android S, SavedAccessPointsWifiSettings is removed, About phone ->
Wi-Fi MAC address should open SavedAccessPointsWifiSettings2 instead of
SavedAccessPointsWifiSettings.

Bug: 158172263
Test: manual
      Click About phone -> Wi-Fi MAC address and see SavedAccessPointsWifiSettings2 .
Change-Id: Ic51f0c4f955e7c7c4a26ddea57923b7c17e6d534