Enable wifi on XL Wifi setup.

In I5b29917af73aac6a82e13ba846a9d5085f9bd523, we removed
relevant code but it was wrong. At least we need to enable
Wifi once when the Activity is created.

Bug: 3186944
Change-Id: I078cdf9b3d8952e6ce7bb3f9b27a4439e82da534
diff --git a/src/com/android/settings/wifi/WifiSettingsForSetupWizardXL.java b/src/com/android/settings/wifi/WifiSettingsForSetupWizardXL.java
index 17c0beb..635f301 100644
--- a/src/com/android/settings/wifi/WifiSettingsForSetupWizardXL.java
+++ b/src/com/android/settings/wifi/WifiSettingsForSetupWizardXL.java
@@ -113,6 +113,10 @@
         getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
         
         mWifiManager = (WifiManager)getSystemService(Context.WIFI_SERVICE);
+        // There's no button here enabling wifi network, so we need to enable it without
+        // users' request.
+        mWifiManager.setWifiEnabled(true);
+
         mWifiSettings =
                 (WifiSettings)getFragmentManager().findFragmentById(R.id.wifi_setup_fragment);
         mInputMethodManager = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);