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
diff --git a/aconfig/launcher_search.aconfig b/aconfig/launcher_search.aconfig
index b846604..4e16e7f 100644
--- a/aconfig/launcher_search.aconfig
+++ b/aconfig/launcher_search.aconfig
@@ -34,3 +34,10 @@
     description: "This flag disables accessibility drag for Private Space Apps."
     bug: "289223923"
 }
+
+flag {
+    name: "private_space_restrict_item_drag"
+    namespace: "launcher_search"
+    description: "This flag disables drag and drop for Private Space Items."
+    bug: "289223923"
+}
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