Fix hotseat predicted app update regression.

Hotseat predicted app updates were only being allowed then the hotseat was invisible or when the workspace was loading. This was too strict. Changed the logic to ignore hotseat visibility when the workspace is loading, when there are empty spots in the hotseat and when the predicted items are unchanged. This ensures the hotseat always has the intended number of icons and that icons can be updated in-place.

Fixes: 172597819

Demo: https://drive.google.com/file/d/100svnqX048Da7vues2p-vvQNN6sIF8v4/view?usp=sharing
Change-Id: I2f93ff44618c0282a6411918c34d70f75ec73b73