Holo fixes

* Fix up ButtonGroup to behave better.
* Fix bad states with holo list selectors.
* Clean up action mode UI components.
* Change action mode UI to use a text button instead of 'X' to dismiss.
* Fixed spinner dropdowns for Holo.Light

Change-Id: Ifc092bd549ffb539d6a3b2ddd95ebd4b114a441f