[WifiSetup] Don't show WiFi assistant card in WifiPickerActivity

Do not create the assistant card if we are in WifiPickerActivity,
which includes setup wizard and account login.

Bug: 16382431
Change-Id: Id5eaa8040eafe5222e1a5c9276a2a10bedebfd71

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

@@ -733,6 +733,10 @@ public class WifiSettings extends RestrictedSettingsFragment
             mWifiAssistantPreference = new WifiAssistantPreference();
         }
 
+        if (getActivity() instanceof WifiPickerActivity) {
+            return false;
+        }
+
         if (NetworkScorerAppManager.getActiveScorer(getActivity()) != null) {
             // A scorer is already enabled; don't show the card.
             return false;