Removing all usage of LauncherProvider

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