Enable feature in config. Expose Dream in public api for unbundled apps.
Unhide package. Add isDreaming() method to service.
Re-arrange the Dream api a bit. (use onStart as hook for subclasses).
Coordinate properly with power manager.
Replace old dock mode (don't fire old intent).
Change-Id: I1318d20cc1613e5d862f2913f2fcdc9719302cf7
Bug: 6921930