Fixing ModelPreload cancelling existing load am: 57d4f748b8 am: d73fa1ef92 am: 83d4b37ff2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15820555

Change-Id: Ia1d7e5c6486b83c9cceed284a8b43cef6a7a8e68