Fix QR code scanner layout in "Pair devices over Wi-Fi" page.

The toolbar needs to be disabled to remove the empty space at the top
of the page. Also added the landscape layout xml.

Bug: 193602141
Test: atest SettingsUnitTests and manual

Change-Id: I30368835979b360a8f09e16f70adf57064784517
(cherry picked from commit fd009229e5)

src/com/android/settings/wifi/dpp/WifiDppBaseActivity.java

@@ -26,7 +26,7 @@ import com.android.settings.R;
 import com.android.settings.SetupWizardUtils;
 import com.android.settings.core.InstrumentedActivity;
 
-abstract class WifiDppBaseActivity extends InstrumentedActivity {
+public abstract class WifiDppBaseActivity extends InstrumentedActivity {
     protected FragmentManager mFragmentManager;
 
     protected abstract void handleIntent(Intent intent);