Update comments around PLATFORM_SECURITY_LEVEL (nyc-dev) Bug: 29881091 am: c63e4295ef am: 89c03f5748 am: 57866742e7 am: 78fb4b616f
am: 90cc058ff0

Change-Id: Ie1e8ff3d6735ad7dce2dd8b48d18154c790fefcf