Implement bug 4500971 - Collapsable action views

Action views may now be flagged as 'collapsable'. This means that the
action menu will always show them in the collapsed state by
default. When selected, the action view will "take over" the
navigation/view side of an action bar until dismissed via the home/up
button.

This feature allows for more long-term exclusive modes akin to
ActionModes but less intrusive. The action menu itself remains
unaffected. Collapsable action views are ideal for things such as
search or categories of tool palettes.

Change-Id: Ibafce5631befbfe67c5d834c2e2617d3d7f6da7a