Invisible by default, not activatable when the platform volume controller is active. However, when the platform volume controller is not active, it can be enabled via a broadcast intent. When enabled, the status bar icon also changes to a single dnd icon. Very little more than embedding the existing zen mode panel into the detail pane of a new QS tile. Change-Id: I1e0ff6fbb99b00f67b53bceda8cbf121f3ef6b52