Also fixing a race condition in model when an item update/delete task
gets queued and executed after the model has reloaded (making the old
data obsolete)
Bug: 277345535
Bug: 263079498
Test: Presubmit
Flag: N/A
Change-Id: Ibd4bdbb3eece05b38b73a22a4be5f368df3754f0
Extract the item finding logic from AddWorkspaceItemsTask
to a separate class and write tests.
Test: AddWorkspaceItemsTaskTest.kt , WorkspaceItemSpaceFinderTest.kt
Bug: 199160559
Change-Id: Ie1bc4fcd4f94cd7cb0601c21bbdf273452b9dd1f