Add Enterprise Privacy page to Settings

This adds a new page to Settings which tells the user about his/her
privacy in light of enterprise management. The new page is only shown
on devices that have a Device Owner app set.

This CL adds a mostly blank page. Follow-up CLs will populate the page
with information about specific admin actions/policies.

The page's title ("Privacy"), icon and location in the Settings app are
tentative. The page will move to its final location once the new IA
redesign is finished.

Test: make RunSettingsRoboTests
BUG: 32692748

Change-Id: I5b5c08c0025207516b0779f54cf68234a4ba3fe4