Make the background of keypopup transparent

Change-Id: I5240ffdd8e48bcb99c2edf878d8efaba2cafeb07

java/res/layout/keyboard_popup.xml

@@ -32,7 +32,7 @@
             android:layout_alignParentBottom="true"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:background="@drawable/keyboard_dark_background"
+            android:background="@color/latinkeyboard_transparent"
 
             latin:keyBackground="@drawable/btn_keyboard_key_gingerbread_popup"
             latin:keyHysteresisDistance="0dip"