change background to surface for bottomsheet

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

app/src/main/java/com/owncloud/android/ui/fragment/GalleryFragmentBottomSheetDialog.kt

@@ -53,7 +53,7 @@ class GalleryFragmentBottomSheetDialog(
     }
 
     private fun setupLayout() {
-        viewThemeUtils.platform.colorViewBackground(binding.bottomSheet, ColorRole.SURFACE_VARIANT)
+        viewThemeUtils.platform.colorViewBackground(binding.bottomSheet, ColorRole.SURFACE)
 
         listOf(
             binding.tickMarkShowImages,