DocsUI M3: Re-style app bar for material 3

Update the sizes, margins and paddings.

Update the Toolbar to the material3 component, removing most of the
style customizations.

Removing actionBarSize to rely on material library default.

Test: Manual build, deploy apk and start it on DUT with flag off
Flag: com.android.documentsui.flags.use_material3
Bug: 377771946, 383172565
Change-Id: I1d456cc74c19d212a007c80f75019e49c6fe8a43