Inline notif pipeline flag into SBNActivityStarter

This change is a no-op; the flag is now enabled-by-default, so all
removed code paths here are effectively dead.

Bug: 200269355
Test: atest SystemUITests
Change-Id: Ib10fa8e96a3abfe55b7ba3ae7d33d8a4e66a1e2f
4 files changed