Show default app icon in default app screen.

- Renamed AdvancedAppSettings to DefaultAppSettings.
- Add logic to DefaultAppPreferenceController to also display icon.
- Modified DefautlAssistPrefController to suppress gear icon, and use
  the controller in default app setting UI to display icon.
- Remove dynamic injected payment setting activity and create the
  setting statically in xml.
- Add DefaultPaymentSettingsPreference to display default payment app
  title (no icon because we can't get it)

Change-Id: I6b8c768da0bafe5ec9a85ba9c79c7993b449be25
Fix: 36458534
Test: robotests

src/com/android/settings/webview/WebViewAppPreferenceController.java

@@ -26,7 +26,6 @@ public class WebViewAppPreferenceController extends DefaultAppPreferenceControll
 
     private static final String WEBVIEW_APP_KEY = "select_webview_provider";
 
-    private final Context mContext;
     private final WebViewUpdateServiceWrapper mWebViewUpdateServiceWrapper;
     private Preference mPreference;
 
@@ -37,7 +36,6 @@ public class WebViewAppPreferenceController extends DefaultAppPreferenceControll
     public WebViewAppPreferenceController(Context context,
             WebViewUpdateServiceWrapper webviewUpdateServiceWrapper) {
         super(context);
-        mContext = context;
         mWebViewUpdateServiceWrapper = webviewUpdateServiceWrapper;
     }