Add checks for FeatureFlags.QSB_ON_FIRST_SCREEN

When false, it correctly does not show the QSB but leaves
a default style search bar which cannot be removed.

Add checks to control default view visibility in device
profile layout & re-layout, QSB container and in
Workspace's onMeasure

Bug: 35967694

Change-Id: I3d0f89e1022d838eeb95762fd1fb3f7257956c41