Move NotifEntryMan and NotifPipeline from NSSL

Move NotificationEntryManager and NotifPipeline from the
NotificationStackScrollLayout and into the
NotificationStackScrollLayoutController.

This cleans up some lingering imports that were hanging about as well.

Bug: 147245740
Test: atest SystemUITests && manual
Change-Id: I9709e3f67e704458b0e12f7939b569ee387c0fd1
6 files changed