[com.google.android.material.bottomsheet] Expanded BottomSheetDialog shouldn't have top insets when it's in the bottom split screen

[ashnohe]

Description:

Expanded BottomSheetDialog shouldn't have top insets when it's in the bottom split screen.

Repro steps:

1. Open app in portrait
2. Open Recents
3. Select "split screen"
4. Press the button to open the BottomSheetDialog
5. Double-tap on the handle between the screens
   ==> App moves to the bottom split screen. Extra top insets above the header.

Expected behavior: there wouldn't be top insets above the header.

This only occurs for expanded bottom sheets. This issue doesn't occur on Android 14. Note edge-to-edge was enforced on Android 15.

Sample app attached.

BottomSheetDialogTest.zip

Android API version:

Android 15 (SDK 35)

Material Library version:

1.13.0-alpha06

Device:

Tested on Pixel Fold