Move some wifi tracking code to SettingsLib

Move tracking of which networks are available/saved and their state
over to SettingsLib to share it with Quick Settings.

Bug: 19180466
Change-Id: Iaeef06b26da8cb38e1ba09a7d105d04d499dc181

src/com/android/settings/wifi/WifiSettingsForSetupWizard.java

@@ -95,8 +95,8 @@ public class WifiSettingsForSetupWizard extends WifiSettings {
     }
 
     @Override
-    protected void updateAccessPoints() {
-        super.updateAccessPoints();
+    public void onAccessPointsChanged() {
+        super.onAccessPointsChanged();
         updateFooter(getPreferenceScreen().getPreferenceCount() == 0);
     }