Simplifying logic for managed for icon addition

> Checking for duplicate icons before adding new icons

For O and above, icon addition is controlled using
SessionCommitReceiver.
As long as the Launcher is the default app, it will keep adding
icons on the homescreen. Apps installed while launcher was
not the default homescreen, no icons will be added.

For below O, icons are added based on package event. As long as
the Launcher process is running, it will keep adding icons on the
homescreen. Apps installed while the launcher app was dead, no
icons will be added.

Bug: 37528649
Bug: 37082950
Bug: 34112546
Change-Id: Ic99501fa476c00474a479f2a36c24614bfa3f4bf

src/com/android/launcher3/Workspace.java

@@ -451,7 +451,7 @@ public class Workspace extends PagedView
         mLauncher.lockScreenOrientation();
         mLauncher.onInteractionBegin();
         // Prevent any Un/InstallShortcutReceivers from updating the db while we are dragging
-        InstallShortcutReceiver.enableInstallQueue();
+        InstallShortcutReceiver.enableInstallQueue(InstallShortcutReceiver.FLAG_DRAG_AND_DROP);
 
         // Do not add a new page if it is a accessible drag which was not started by the workspace.
         // We do not support accessibility drag from other sources and instead provide a direct
@@ -504,7 +504,8 @@ public class Workspace extends PagedView
         mLauncher.unlockScreenOrientation(false);
 
         // Re-enable any Un/InstallShortcutReceiver and now process any queued items
-        InstallShortcutReceiver.disableAndFlushInstallQueue(getContext());
+        InstallShortcutReceiver.disableAndFlushInstallQueue(
+                InstallShortcutReceiver.FLAG_DRAG_AND_DROP, getContext());
 
         mOutlineProvider = null;
         mDragInfo = null;