[DocsUI M3] Restyle the nav tree in drawer layout

The toolbar inside the drawer is removed as per spec.

Check the demo in the bug item.

Bug: 381959113
Test: Manual inpsection
Flag: com.android.documentsui.flags.use_material3
Change-Id: I4de1377afb5f6a0e629ab183b5c27c8ac98a71c4