Create a page to manage dnd permission for individual app

- Change the original ZenAccessPage to
  - Remove the inline switch
  - Make the preference click target go into the new detail page
  - Some formatting/style change.

- Create a new detail page for zen access.
  - Exit if app didn't declare this permission
  - Preset the switch toggle to their current permission grant state
  - Move the warning dialog logic from ZenAccessSettings to here.

- Move some common functionality into ZenAccessController, a static
  helper class

Bug: 128547723
Test: robotest
Change-Id: I1ebb32396869d07ff4283b300bd716506298c9b5