Action bar rendering in layoutlib [DO NOT MERGE]

This also makes a couple of changes to the framework:
1. ShareActionProvider - Use edit mode to execute activity chooser code.
2. ActionBarImpl - add a new constructor for use by layoutlib.

This also relies on some changes to the plugin to pass the correct params.

Change-Id: Ia30fef816afd91ec1e439734d56b59b1323bfee2
(cherry-picked from 14bf0cef)