[BottomSheet] Updated a11y focus to move to bottom sheet when expande…

…d and siblings are hidden from a11y services.

PiperOrigin-RevId: 320631879

lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java

@@ -44,6 +44,7 @@
 import android.view.ViewConfiguration;
 import android.view.ViewGroup;
 import android.view.ViewParent;
+import android.view.accessibility.AccessibilityEvent;
 import androidx.annotation.FloatRange;
 import androidx.annotation.IntDef;
 import androidx.annotation.NonNull;
@@ -1677,6 +1678,10 @@ private void updateImportantForAccessibility(boolean expanded) {
 
     if (!expanded) {
       importantForAccessibilityMap = null;
+    } else if (updateImportantForAccessibilityOnSiblings) {
+      // If the siblings of the bottom sheet have been set to not important for a11y, move the focus
+      // to the bottom sheet when expanded.
+      viewRef.get().sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
     }
   }