Remove reference to system theme

This change also introduces
 * Background for space key preview
 * Tune stone theme

Change-Id: I84fca0baf2392582da870d2ff77b3e99c28faf7b
diff --git a/java/res/values/keyboard-icons-ics.xml b/java/res/values/keyboard-icons-ics.xml
index feb95f8..86fb7bb 100644
--- a/java/res/values/keyboard-icons-ics.xml
+++ b/java/res/values/keyboard-icons-ics.xml
@@ -15,7 +15,7 @@
 -->
 
 <resources>
-    <style name="KeyboardIcons.IceCreamSandwich" parent="android:Theme.Holo">
+    <style name="KeyboardIcons.IceCreamSandwich">
         <!-- Keyboard icons -->
         <!-- TODO: The following holo icon for phone (drawable-hdpi and drawable-xhdpi) are too
              large for phone.