Update the N Preview docs now that Studio 2.1 is stable. bug: 28342771 am: 96e6abb
am: 39a59d0

* commit '39a59d0c45df2fd724dde27caaab7622f1994673':
  Update the N Preview docs now that Studio 2.1 is stable. bug: 28342771

Change-Id: I24fe1b61520c956e61c490b96ae8bd98b5aed017