[Provider Model] Update Wi-Fi SSID in APM networks type

- Check Wi-Fi connected then update the SSID to summary

- Screenshot
  https://screenshot.googleplex.com/BWHAAqb7q8XaK9T

Bug: 178915286
Test: manual test
- atest InternetPreferenceControllerTest

Change-Id: I9efc2f62b7b241a4a63d0514158c8e76f0d6acc2

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

@@ -98,4 +98,11 @@ public final class WifiSummaryUpdater extends SummaryUpdater {
                 com.android.settingslib.R.string.preference_summary_default_combination,
                 ssid, mWifiTracker.statusLabel);
     }
+
+    /**
+     * return true if Wi-Fi connected.
+     */
+    public boolean isWifiConnected() {
+        return mWifiTracker.connected;
+    }
 }