Log shortcuts open on ACTION_UP instead of in showForIcon().

- We only want to log when the container is opened and potentially
  used, not when a long press is followed by a drag-and-drop.
- Also cleaned up code that was determining the container of the
  app icon, since LaunchSourceProvider.fillInLaunchSourceData()
  can do that instead (it's more robust and consistent).

Bug: 30791570
Change-Id: I05b6750f26182fda8a9940ac66f1371c2d228ca9