Bug 1150742 - Remove new from tablet_tab_close. r=mhaigh

tablet_* is not ideal but there is a collision between phone and tablet assets
so I filed bug 1193585 to complete this process.

mobile/android/base/resources/drawable-large-v11/new_tablet_tab_item_close_button.xml

@@ -7,12 +7,12 @@
 
     <!-- pressed state -->
     <item android:state_pressed="true"
-          android:drawable="@drawable/new_tablet_tab_close_active"/>
+          android:drawable="@drawable/tablet_tab_close_active"/>
 
     <item android:state_checked="true"
-          android:drawable="@drawable/new_tablet_tab_close_active"/>
+          android:drawable="@drawable/tablet_tab_close_active"/>
 
     <!-- normal mode -->
-    <item android:drawable="@drawable/new_tablet_tab_close"/>
+    <item android:drawable="@drawable/tablet_tab_close"/>
 
 </selector>

mobile/android/base/resources/layout-large-v11/tab_strip_item_view.xml

@@ -46,7 +46,7 @@
         android:background="@android:color/transparent"
         android:scaleType="center"
         android:contentDescription="@string/close_tab"
-        android:src="@drawable/new_tablet_tab_close"
+        android:src="@drawable/tablet_tab_close"
         android:duplicateParentState="true"/>
 
 </merge>