Make it so that the app's explanation comes before the list of possible
policies. This gives the app a chance to explain itself instead of having
the explanation hidden below the fold. To avoid situations in which one
bunch of text items can obscure the other, use an expandable/ellipsizable
TextView with an indicator image. This resolves b/2992594.
Change-Id: I0eb0d0c46bb4be2ec2e019d741915537e1fcc592
Improve the look of the UI, and add the confirmation screen
for enabling an administrator. This uses the new framework APIs
to show its description and policies it will control.
