What this adds:
- A new Intent activity flag to completely replace an existing task.
- A new Intent activity flag to bring the current home task up behind
a new task being started/brought to the foreground.
- New versions of startActivity() that take an array of Intents to be
started, allowing applications to start a task in a specific state.
- A public moveTaskToFront() method on ActivityManager, with a new flag
that allows the caller to have the task moved to the front with the
current home task immediately behind it.
Change-Id: Ie8028d09acffb5349d98043c67676daba09f75c8
621e17de87