Permissions theme fixing

 - Mostly just paddings a whatnot for preferences.
 - Also fix additional permissions screen (and its back arrow).
 - Keep ManagePermissions preferences around so that summary reloads
   aren't as painful on resume.

Bug: 21636268
Bug: 21642971
Change-Id: Ibeb96ce63017c90fc37a661a6d82218b57371fb3