[DocsUI M3] Fix unit bar alignment issue

* Make the Name header to vertically align with the thumbnail in
  the list view.
* Restructure the layout to remove unnecessary LinearLayout.
* Remove icon_wrapper id for list view because it's not used any
  more, and update the bot file for the test.

Check the attached bug for the demo.

Bug: 409697194
Test: m DocumentsUIGoogle && manual inspection
Flag: com.android.documentsui.flags.use_material3
Change-Id: I4e63877d2b907701237c588b4cf747c7d67ad7d3