Bug 1214602 - Bring back single column layout for tabs tray. r=margaret

This patch will use the single column list on phones in portrait mode
again. In landscape mode the multi column grid will be used.

In addition to that this patch removes the Nightly flag (Bug 1204917).

--HG--
extra : commitid : Cw6uqgLYChb
extra : rebase_source : d9e45369adb0bba89f0376c6756eddafc6d71ae1

mobile/android/base/tabs/TabsPanel.java

@@ -26,6 +26,7 @@ import org.mozilla.gecko.widget.GeckoPopupMenu;
 import org.mozilla.gecko.widget.IconTabWidget;
 
 import android.content.Context;
+import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.graphics.Rect;
 import android.util.AttributeSet;
@@ -74,7 +75,9 @@ public class TabsPanel extends LinearLayout
 
 
     public static View createTabsLayout(final Context context, final AttributeSet attrs) {
-        if (HardwareUtils.isTablet() || AppConstants.NIGHTLY_BUILD) {
+        final boolean isLandscape = context.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE;
+
+        if (HardwareUtils.isTablet() || isLandscape) {
             return new TabsGridLayout(context, attrs);
         } else {
             return new TabsListLayout(context, attrs);