Preventing DragAndDrop for PS apps.

This Cl restricts item dragging for PS apps from
all launcher surfaces such as AllApps, AppPredictionRow, etc.

Video: https://photos.app.goo.gl/PKGw8n23hJVJMyUk7

Flag: ACONFIG com.android.launcher3.Flags.private_space_restrict_item_drag DEVELOPMENT
Bug: 289223923
Test: Ran Launcher3 tests
Change-Id: I2c5dbaa325095ec63aedf39b6b2c269f745d58ca