Invalidate stale BgDataModel when predictions are disabled

Launcher stores ItemInfos for cached predictions in list BgDataModel.cachedPredictedItems  on Launcher start (LoaderTask#run). The list reused if launcher has to rebind UI. Hence, the list should be cleared if launcher receives empty predictions.

Bug: 161245294
Test: Manual
Change-Id: I275655d5f52f6a6e5297473dd2f642728c1964a6
1 file changed