SystemUI: Add Lineage statusbar item holder

*) To be used as a layout to hold one or more lineage-sdk status bar
   feature classes.

*) Propagates visibility and tint information via interfaces
   defined in lineage-sdk internal.

*) Supports adding further interfaces without impacting existing use
   cases.

Change-Id: I4d4361fcb682c1940133bee1029b8b759f93e05f