Improve restore icon treatment

This is the first of a few CL's that change the way pending/downloading/installing apps look to follow the new mocks. In this CL we:

-Fix a regression where the track path doesn't show up when downloading an app
-Change the sizes of icons to reflect the new design mock
-Add skeleton motion animation

In upcoming CL's we will add visual polish and make sure it matches the motion spec exactly

Bug: 254858049
Test: Download an app and check pending, downloading, and installing visuals
Change-Id: Ief1038ea52d77874b4031db76d51a2787615a14d