Ensure nav rail respects the window insets as well

When the nav rail layout is used, it currently doesn't get inset by the
requested amount. This updates to ensure that all 3 layouts and all the
containers are properly inset.

Bug: 402604097
Test: m DocumentsUIGoogle and inspect Pixel Tablet in portrait mode
Flag: com.android.documentsui.flags.use_material3
Change-Id: I2fc935b47aac7c3107e380acac16c6c942a0f1cf