Merge \\\"docs: Describe how to update N Preview test devices on N release\\\"...
Merge \\\"docs: Describe how to update N Preview test devices on N release\\\" into nyc-dev am: 085b4e8f am: 9ef754c1
am: 3b6d0481
Change-Id: I99a0a848f4808e01a3aaa552f1de62ea5e2d43f7