DocsUI M3: Move parts of the app bar around

This CL mostly just move things around, follow up restyles them.

Move the buttons/menu-items: sub_menu_grid and sub_menu_list from the
sub_menu to options_menu_search. Update logic handling their
visibility to account for this move.

Move the breadcrumb to the bottom without re-styling it yet, so its
appearance isn't ideal yet.

Update the Snackbars to be anchored on coordinator_layout instead of
container_save because it snackbar messages were pushing the breadcrumb
up when displaying the message.

Test: Manual build, deploy apk and start it on DUT with flag off
Flag: com.android.documentsui.flags.use_material3
Bug: 377771946
Change-Id: Ie27cf066a65a7a89931c1f16c537dcedd0008f22